diff --git a/plugins/_bundled/sirsoft-pay_kginicis/CHANGELOG.md b/plugins/_bundled/sirsoft-pay_kginicis/CHANGELOG.md
index 7f303241..c7dc1975 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/CHANGELOG.md
+++ b/plugins/_bundled/sirsoft-pay_kginicis/CHANGELOG.md
@@ -30,6 +30,8 @@
 - 표준/모바일 결제 서명 API에서 현재 모드의 MID와 서명키가 준비되지 않은 경우 서명을 생성하지 않고 중단하도록 보강했습니다.
 - PC/모바일/CBT 결제 콜백에서 로컬 결제완료 저장 후 예외가 발생한 경우 PG 취소·환불 보상 호출을 건너뛰도록 보강했습니다. 로컬 주문은 결제완료인데 PG 거래만 취소되는 상태 불일치를 방지합니다.
 - 일본 편의점결제(CBT CVS) 만료 처리와 통보 이력 저장 시 결제 row를 잠근 뒤 최신 상태를 다시 확인하도록 보강해 입금통보와 관리자 만료 처리의 동시성 충돌 가능성을 줄였습니다.
+- 통화 스냅샷의 환율 설정이 비정상인 주문은 표준/모바일/CBT/가상계좌 결제 흐름에서 서버 오류 대신 검증 실패 또는 재통보 가능한 응답으로 처리하도록 보강했습니다.
+- PC/모바일/CBT/가상계좌 결제 완료 콜백을 주문 단위로 직렬화해 완전 동시 콜백에서 결제완료 후속 처리 훅이 중복 실행될 가능성을 줄였습니다.
 
 ### Fixed
 
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Concerns/SerializesPaymentCallbacks.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Concerns/SerializesPaymentCallbacks.php
new file mode 100644
index 00000000..6b6f8390
--- /dev/null
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Concerns/SerializesPaymentCallbacks.php
@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Plugins\Sirsoft\PayKginicis\Concerns;
+
+use Illuminate\Contracts\Cache\LockTimeoutException;
+use Illuminate\Support\Facades\Cache;
+use Illuminate\Support\Facades\Log;
+
+trait SerializesPaymentCallbacks
+{
+    protected function acquireOrderCallbackLock(string $context, string $orderNumber): mixed
+    {
+        $key = $this->callbackLockKey($context, $orderNumber);
+        $lock = Cache::lock($key, $this->callbackLockTtlSeconds());
+
+        try {
+            $lock->block($this->callbackLockWaitSeconds());
+        } catch (LockTimeoutException $e) {
+            Log::warning('KG Inicis: callback lock timeout', [
+                'context' => $context,
+                'order_number' => $orderNumber,
+                'lock_key' => $key,
+            ]);
+
+            throw $e;
+        }
+
+        return $lock;
+    }
+
+    protected function releaseOrderCallbackLock(mixed $lock): void
+    {
+        if (is_object($lock) && method_exists($lock, 'release')) {
+            $lock->release();
+        }
+    }
+
+    protected function callbackLockKey(string $context, string $orderNumber): string
+    {
+        return 'sirsoft-pay_kginicis:callback:'
+            . $context
+            . ':'
+            . sha1(trim($orderNumber));
+    }
+
+    protected function callbackLockTtlSeconds(): int
+    {
+        return 30;
+    }
+
+    protected function callbackLockWaitSeconds(): int
+    {
+        return 10;
+    }
+}
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Concerns/ValidatesCbtOrderContext.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Concerns/ValidatesCbtOrderContext.php
index f89325f7..b8fd6d2d 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Concerns/ValidatesCbtOrderContext.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Concerns/ValidatesCbtOrderContext.php
@@ -4,7 +4,9 @@ declare(strict_types=1);
 
 namespace Plugins\Sirsoft\PayKginicis\Concerns;
 
+use InvalidArgumentException;
 use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Log;
 use Modules\Sirsoft\Ecommerce\Models\Order;
 use Modules\Sirsoft\Ecommerce\Models\OrderAddress;
 use Modules\Sirsoft\Ecommerce\Services\CurrencyConversionService;
@@ -24,6 +26,33 @@ trait ValidatesCbtOrderContext
         return $this->expectedPaymentPrice($order);
     }
 
+    protected function resolveExpectedPaymentPriceOrNull(Order $order, string $context, array $logContext = []): ?int
+    {
+        try {
+            return $this->expectedPaymentPrice($order);
+        } catch (InvalidArgumentException $e) {
+            $this->logInvalidPaymentCurrency($order, $e, $context, $logContext);
+
+            return null;
+        }
+    }
+
+    protected function logInvalidPaymentCurrency(
+        Order $order,
+        InvalidArgumentException $e,
+        string $context,
+        array $logContext = [],
+    ): void {
+        Log::error('KG Inicis: payment currency is not chargeable', array_merge([
+            'context' => $context,
+            'order_id' => $order->id,
+            'order_number' => $order->order_number,
+            'currency' => $order->currency,
+            'currency_snapshot' => $order->currency_snapshot,
+            'error' => $e->getMessage(),
+        ], $logContext));
+    }
+
     protected function requestMatchesOrderBuyer(Request $request, Order $order): bool
     {
         /** @var OrderAddress|null $address */
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/CbtCallbackController.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/CbtCallbackController.php
index 7117f914..af5ce159 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/CbtCallbackController.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/CbtCallbackController.php
@@ -10,11 +10,12 @@ use Illuminate\Http\RedirectResponse;
 use Illuminate\Support\Facades\Log;
 use Modules\Sirsoft\Ecommerce\Enums\PaymentStatusEnum;
 use Modules\Sirsoft\Ecommerce\Models\Order;
-use Modules\Sirsoft\Ecommerce\Services\CurrencyConversionService;
 use Modules\Sirsoft\Ecommerce\Services\OrderProcessingService;
 use Plugins\Sirsoft\PayKginicis\Concerns\IssuesReceiptCookie;
 use Plugins\Sirsoft\PayKginicis\Concerns\PreventsReplayCallback;
+use Plugins\Sirsoft\PayKginicis\Concerns\SerializesPaymentCallbacks;
 use Plugins\Sirsoft\PayKginicis\Http\Requests\CbtCallbackRequest;
+use Plugins\Sirsoft\PayKginicis\Concerns\ValidatesCbtOrderContext;
 use Plugins\Sirsoft\PayKginicis\Services\CbtReconciliationService;
 use Plugins\Sirsoft\PayKginicis\Services\KgInicisApiService;
 
@@ -31,6 +32,8 @@ class CbtCallbackController
 {
     use IssuesReceiptCookie;
     use PreventsReplayCallback;
+    use SerializesPaymentCallbacks;
+    use ValidatesCbtOrderContext;
 
     private const PLUGIN_IDENTIFIER = 'sirsoft-pay_kginicis';
 
@@ -167,6 +170,7 @@ class CbtCallbackController
         // Approve 성공 후 후속 처리 실패 시 PG 자동 cancel 추적 변수.
         $approvedTid = null;
         $approvedAmount = 0;
+        $callbackLock = null;
 
         try {
             $order = $this->orderService->findByOrderNumber($oid);
@@ -177,6 +181,8 @@ class CbtCallbackController
                 return redirect($this->resolveFailUrl(['error' => 'order_not_found', 'orderId' => $oid]));
             }
 
+            $callbackLock = $this->acquireOrderCallbackLock('cbtAuthCallback', $oid);
+
             $this->assertPayableCbtOrder($order);
 
             $pgResponse = $this->apiService->approveCbtPayment($sid);
@@ -221,9 +227,6 @@ class CbtCallbackController
             }
 
             $this->assertCbtApproveResponseMatchesOrder($order, $pgResponse, $request, $payMethod);
-            // PG 승인금액이 누락되어 검증 예외가 발생해도 자동환불 대사 레코드에는 결제 통화 청구액을 남긴다
-            // (buildPgPaymentData 와 동일 SSoT — base≠결제 통화에서도 PG 청구 통화와 단위 일치).
-            $approvedAmount = app(CurrencyConversionService::class)->resolveOrderPaymentChargeAmount($order);
             $approvedAmount = $this->resolveApprovedAmount($pgResponse, $order);
             $authResponse = $this->sanitizePgResponse($request->except(['_token']), self::CBT_AUTH_RESPONSE_KEYS);
             $approveResponse = $this->sanitizePgResponse($pgResponse, self::CBT_APPROVE_RESPONSE_KEYS);
@@ -293,6 +296,8 @@ class CbtCallbackController
             );
 
             return redirect($this->resolveFailUrl(['error' => 'cbt_failed', 'orderId' => $oid]));
+        } finally {
+            $this->releaseOrderCallbackLock($callbackLock);
         }
     }
 
@@ -396,8 +401,14 @@ class CbtCallbackController
         // 결제 청구액 SSoT = 결제 통화(order_currency) 환산액 (buildPgPaymentData 와 동일 기준).
         // CBT 는 order_currency=JPY 강제이나 base 통화는 다를 수 있어(예: base KRW, 결제 JPY)
         // total_due_amount(base) 직접 비교 시 PG 승인액(JPY)과 단위가 어긋난다.
-        $expectedAmount = app(CurrencyConversionService::class)->resolveOrderPaymentChargeAmount($order);
         $pgAmount = $this->firstNonEmptyString($pgResponse, ['amount', 'price', 'bokuApplPrice', 'bokuLocalApplPrice']);
+        $expectedAmount = $this->resolveExpectedPaymentPriceOrNull($order, 'cbt_approve', [
+            'tid' => $pgResponse['tid'] ?? ($pgResponse['transactionId'] ?? null),
+            'received_amount' => $pgAmount,
+        ]);
+        if ($expectedAmount === null) {
+            throw new \RuntimeException('KG Inicis CBT payment currency is not chargeable.');
+        }
 
         // 일본 CBT 승인 응답은 금액 필드가 비어 온다(매뉴얼상 미사용). 금액이 없으면
         // 주문 결제예정액을 승인액으로 신뢰한다(승인 권위 = resultCode OK + tid).
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileCallbackController.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileCallbackController.php
index d5680808..79ffd303 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileCallbackController.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileCallbackController.php
@@ -15,6 +15,8 @@ use Plugins\Sirsoft\PayKginicis\Concerns\IssuesReceiptCookie;
 use Plugins\Sirsoft\PayKginicis\Concerns\PreventsReplayCallback;
 use Plugins\Sirsoft\PayKginicis\Concerns\ResolvesEasyPaySelection;
 use Plugins\Sirsoft\PayKginicis\Concerns\SanitizesPgResponse;
+use Plugins\Sirsoft\PayKginicis\Concerns\SerializesPaymentCallbacks;
+use Plugins\Sirsoft\PayKginicis\Concerns\ValidatesCbtOrderContext;
 use Plugins\Sirsoft\PayKginicis\Http\Requests\MobileCallbackRequest;
 use Plugins\Sirsoft\PayKginicis\Services\KgInicisApiService;
 
@@ -33,6 +35,8 @@ class MobileCallbackController
     use PreventsReplayCallback;
     use ResolvesEasyPaySelection;
     use SanitizesPgResponse;
+    use SerializesPaymentCallbacks;
+    use ValidatesCbtOrderContext;
 
     private const PLUGIN_IDENTIFIER = 'sirsoft-pay_kginicis';
 
@@ -172,6 +176,7 @@ class MobileCallbackController
         // cancelPayment 를 호출해 PG 잔존 승인을 해제한다 (사용자 환불 보장).
         $approvedTid = null;
         $approvedTotPrice = 0;
+        $callbackLock = null;
 
         try {
             $order = $this->orderService->findByOrderNumber($moid);
@@ -182,6 +187,8 @@ class MobileCallbackController
                 return redirect($this->resolveFailUrl(['error' => 'order_not_found', 'orderId' => $moid]));
             }
 
+            $callbackLock = $this->acquireOrderCallbackLock('mobileAuthCallback', $moid);
+
             // 서버 승인 요청: POST P_REQ_URL with P_MID + P_TID
             $result = $this->apiService->authorizeMobilePayment($reqUrl, $pTid);
 
@@ -228,6 +235,21 @@ class MobileCallbackController
             $approvedTotPrice = $totPrice;
             $embeddedPgProvider = $this->resolveEmbeddedPgProvider($selectedEasyPayMethod);
 
+            $expectedAmount = $this->resolveExpectedPaymentPriceOrNull($order, 'mobile_auth_callback', [
+                'tid' => $tid,
+                'received_amount' => $totPrice,
+            ]);
+            if ($expectedAmount === null) {
+                $this->autoCancelIfApproved($approvedTid, $moid, $approvedTotPrice, 'invalid_payment_currency');
+
+                return redirect($this->resolveFailUrl(['error' => 'invalid_payment_currency', 'orderId' => $moid]));
+            }
+            if ($expectedAmount > 0 && $totPrice !== $expectedAmount) {
+                $this->autoCancelIfApproved($approvedTid, $moid, $approvedTotPrice, 'amount_mismatch');
+
+                return redirect($this->resolveFailUrl(['error' => 'amount_mismatch', 'orderId' => $moid]));
+            }
+
             Log::info('KG Inicis mobile: completing card payment', [
                 'P_OID' => $moid,
                 'P_TID' => $tid,
@@ -298,6 +320,8 @@ class MobileCallbackController
                 'message' => $e->getMessage(),
                 'orderId' => $moid,
             ]));
+        } finally {
+            $this->releaseOrderCallbackLock($callbackLock);
         }
     }
 
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileSignatureController.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileSignatureController.php
index 8b712482..a0f38bb0 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileSignatureController.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/MobileSignatureController.php
@@ -107,7 +107,17 @@ class MobileSignatureController
             ], 403);
         }
 
-        if ($price !== $this->expectedPaymentPrice($order)) {
+        $expectedPrice = $this->resolveExpectedPaymentPriceOrNull($order, 'mobile_signature', [
+            'received_amount' => $price,
+        ]);
+        if ($expectedPrice === null) {
+            return response()->json([
+                'success' => false,
+                'message' => 'Payment currency is not chargeable.',
+            ], 422);
+        }
+
+        if ($price !== $expectedPrice) {
             return response()->json([
                 'success' => false,
                 'message' => 'Payment amount does not match the order amount.',
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCallbackController.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCallbackController.php
index 85ba2800..b359c92c 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCallbackController.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCallbackController.php
@@ -16,12 +16,13 @@ use Modules\Sirsoft\Ecommerce\Enums\PaymentStatusEnum;
 use Modules\Sirsoft\Ecommerce\Exceptions\PaymentAmountMismatchException;
 use Modules\Sirsoft\Ecommerce\Helpers\DeviceDetector;
 use Modules\Sirsoft\Ecommerce\Models\Order;
-use Modules\Sirsoft\Ecommerce\Services\CurrencyConversionService;
 use Modules\Sirsoft\Ecommerce\Services\OrderProcessingService;
 use Plugins\Sirsoft\PayKginicis\Concerns\IssuesReceiptCookie;
 use Plugins\Sirsoft\PayKginicis\Concerns\PreventsReplayCallback;
 use Plugins\Sirsoft\PayKginicis\Concerns\ResolvesEasyPaySelection;
 use Plugins\Sirsoft\PayKginicis\Concerns\SanitizesPgResponse;
+use Plugins\Sirsoft\PayKginicis\Concerns\SerializesPaymentCallbacks;
+use Plugins\Sirsoft\PayKginicis\Concerns\ValidatesCbtOrderContext;
 use Plugins\Sirsoft\PayKginicis\Http\Requests\AuthCallbackRequest;
 use Plugins\Sirsoft\PayKginicis\Http\Requests\MobileVbankNotifyRequest;
 use Plugins\Sirsoft\PayKginicis\Http\Requests\VbankNotifyRequest;
@@ -40,6 +41,8 @@ class PaymentCallbackController
     use PreventsReplayCallback;
     use ResolvesEasyPaySelection;
     use SanitizesPgResponse;
+    use SerializesPaymentCallbacks;
+    use ValidatesCbtOrderContext;
 
     private const PLUGIN_IDENTIFIER = 'sirsoft-pay_kginicis';
 
@@ -223,6 +226,7 @@ class PaymentCallbackController
         $authUrl = $receivedAuthUrl;
         $netCancelUrl = $this->apiService->resolveIdcNetCancelUrl($idcName);
         $tid = '';
+        $callbackLock = null;
 
         try {
             $order = $this->orderService->findByOrderNumber($moid);
@@ -233,6 +237,8 @@ class PaymentCallbackController
                 return redirect($this->resolveFailUrl(['error' => 'order_not_found', 'orderId' => $moid]));
             }
 
+            $callbackLock = $this->acquireOrderCallbackLock('authCallback', $moid);
+
             HookManager::doAction('sirsoft-pay_kginicis.payment.before_authorize', $order, $validated);
 
             $pgResponse = $this->apiService->authorizePayment($authUrl, $authToken);
@@ -280,6 +286,21 @@ class PaymentCallbackController
                 $totPrice = (int) ($pgResponse['TotPrice'] ?? $pgResponse['totPrice'] ?? 0);
             }
 
+            $expectedAmount = $this->resolveExpectedPaymentPriceOrNull($order, 'auth_callback', [
+                'tid' => $tid,
+                'received_amount' => $totPrice,
+            ]);
+            if ($expectedAmount === null) {
+                $this->apiService->sendNetCancel($netCancelUrl, $authToken);
+
+                return redirect($this->resolveFailUrl(['error' => 'invalid_payment_currency', 'orderId' => $moid]));
+            }
+            if ($expectedAmount > 0 && $totPrice !== $expectedAmount) {
+                $this->apiService->sendNetCancel($netCancelUrl, $authToken);
+
+                return redirect($this->resolveFailUrl(['error' => 'amount_mismatch', 'orderId' => $moid]));
+            }
+
             $embeddedPgProvider = $this->resolveEmbeddedPgProvider($selectedEasyPayMethod);
 
             Log::info('KG Inicis: completing card payment', [
@@ -352,6 +373,8 @@ class PaymentCallbackController
                 'message' => $e->getMessage(),
                 'orderId' => $moid,
             ]));
+        } finally {
+            $this->releaseOrderCallbackLock($callbackLock);
         }
     }
 
@@ -376,6 +399,8 @@ class PaymentCallbackController
             'bank' => $validated['nm_inputbank'] ?? null,
         ]);
 
+        $callbackLock = null;
+
         try {
             $order = $this->orderService->findByOrderNumber($moid);
 
@@ -385,6 +410,8 @@ class PaymentCallbackController
                 return response('FAIL', 200)->header('Content-Type', 'text/plain');
             }
 
+            $callbackLock = $this->acquireOrderCallbackLock('vbankNotify', $moid);
+
             if ($this->wasAlreadyPaid($tid)) {
                 $this->logReplayDetected($tid, $moid, 'PC vbankNotify');
 
@@ -430,6 +457,8 @@ class PaymentCallbackController
             ]);
 
             return response('FAIL', 200)->header('Content-Type', 'text/plain');
+        } finally {
+            $this->releaseOrderCallbackLock($callbackLock);
         }
     }
 
@@ -467,6 +496,8 @@ class PaymentCallbackController
             'bank' => $validated['P_FN_NM'] ?? null,
         ]);
 
+        $callbackLock = null;
+
         try {
             $order = $this->orderService->findByOrderNumber($moid);
 
@@ -476,6 +507,8 @@ class PaymentCallbackController
                 return response('FAIL', 200)->header('Content-Type', 'text/plain');
             }
 
+            $callbackLock = $this->acquireOrderCallbackLock('mobileVbankNotify', $moid);
+
             if ($this->wasAlreadyPaid($tid)) {
                 $this->logReplayDetected($tid, $moid, 'mobile vbankNotify');
 
@@ -521,6 +554,8 @@ class PaymentCallbackController
             ]);
 
             return response('FAIL', 200)->header('Content-Type', 'text/plain');
+        } finally {
+            $this->releaseOrderCallbackLock($callbackLock);
         }
     }
 
@@ -599,7 +634,15 @@ class PaymentCallbackController
 
         // 결제 청구액 SSoT = 결제 통화(order_currency) 환산액 (buildPgPaymentData 와 동일 기준).
         // base≠결제 통화에서 PG 통보 금액(환산 통화)과 단위가 일치하도록 한다.
-        $expectedAmount = app(CurrencyConversionService::class)->resolveOrderPaymentChargeAmount($order);
+        $expectedAmount = $this->resolveExpectedPaymentPriceOrNull($order, 'vbank_notify', [
+            'source' => $source,
+            'tid' => $notify['tid'],
+            'received_amount' => $notify['amount'],
+        ]);
+        if ($expectedAmount === null) {
+            return false;
+        }
+
         if ($expectedAmount > 0 && $notify['amount'] !== $expectedAmount) {
             Log::warning('KG Inicis: vbank notify rejected - amount mismatch', [
                 'source' => $source,
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCloseReportController.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCloseReportController.php
index 014e238d..30553835 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCloseReportController.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentCloseReportController.php
@@ -65,7 +65,16 @@ class PaymentCloseReportController
             ]);
         }
 
-        if ($price !== $this->expectedPaymentPrice($order)) {
+        $expectedPrice = $this->resolveExpectedPaymentPriceOrNull($order, 'close_report', [
+            'received_amount' => $price,
+        ]);
+        if ($expectedPrice === null) {
+            return ResponseHelper::error('messages.failed', 422, [
+                'message' => ['Payment currency is not chargeable.'],
+            ]);
+        }
+
+        if ($price !== $expectedPrice) {
             return ResponseHelper::error('messages.failed', 422, [
                 'message' => ['Payment amount does not match the order amount.'],
             ]);
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentSignatureController.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentSignatureController.php
index c730183f..e86b22f3 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentSignatureController.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Controllers/PaymentSignatureController.php
@@ -108,7 +108,17 @@ class PaymentSignatureController
             ], 403);
         }
 
-        if ($price !== $this->expectedPaymentPrice($order)) {
+        $expectedPrice = $this->resolveExpectedPaymentPriceOrNull($order, 'signature', [
+            'received_amount' => $price,
+        ]);
+        if ($expectedPrice === null) {
+            return response()->json([
+                'success' => false,
+                'message' => 'Payment currency is not chargeable.',
+            ], 422);
+        }
+
+        if ($price !== $expectedPrice) {
             return response()->json([
                 'success' => false,
                 'message' => 'Payment amount does not match the order amount.',
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/src/Services/CbtCvsOperationsService.php b/plugins/_bundled/sirsoft-pay_kginicis/src/Services/CbtCvsOperationsService.php
index 2bfb7934..81e07227 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/src/Services/CbtCvsOperationsService.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/src/Services/CbtCvsOperationsService.php
@@ -10,16 +10,19 @@ use Illuminate\Support\Facades\Log;
 use Modules\Sirsoft\Ecommerce\Enums\PaymentStatusEnum;
 use Modules\Sirsoft\Ecommerce\Models\Order;
 use Modules\Sirsoft\Ecommerce\Models\OrderPayment;
-use Modules\Sirsoft\Ecommerce\Services\CurrencyConversionService;
 use Modules\Sirsoft\Ecommerce\Services\OrderProcessingService;
 use Plugins\Sirsoft\PayKginicis\Concerns\PreventsReplayCallback;
 use Plugins\Sirsoft\PayKginicis\Concerns\SanitizesPgResponse;
+use Plugins\Sirsoft\PayKginicis\Concerns\SerializesPaymentCallbacks;
+use Plugins\Sirsoft\PayKginicis\Concerns\ValidatesCbtOrderContext;
 use Plugins\Sirsoft\PayKginicis\Repositories\CbtCvsOperationsRepositoryInterface;
 
 class CbtCvsOperationsService
 {
     use PreventsReplayCallback;
     use SanitizesPgResponse;
+    use SerializesPaymentCallbacks;
+    use ValidatesCbtOrderContext;
 
     private const HISTORY_LIMIT = 20;
 
@@ -64,6 +67,7 @@ class CbtCvsOperationsService
         $amount = (int) ($payload['amount'] ?? 0);
         $payment = null;
         $existingMeta = [];
+        $callbackLock = null;
 
         if ($tid === '' || $orderId === '' || $mid === '' || $amount <= 0) {
             Log::warning('KG Inicis CBT CVS: invalid notify payload', [
@@ -85,6 +89,8 @@ class CbtCvsOperationsService
                 return $this->notifyResult('FAIL', 'failed', 'order_not_found');
             }
 
+            $callbackLock = $this->acquireOrderCallbackLock('cbtCvsNotify', $orderId);
+
             $payment = $this->repository->firstPaymentForOrder($order);
             if (! $payment) {
                 Log::warning('KG Inicis CBT CVS: payment row not found', [
@@ -177,6 +183,16 @@ class CbtCvsOperationsService
             }
 
             $expectedAmount = $this->resolveExpectedCvsAmount($order, $existingMeta);
+            if ($expectedAmount === null) {
+                $this->storeNotifyHistory($payment, $existingMeta, $payload, 'failed', 'invalid_payment_currency', $source, $remoteIp);
+                Log::warning('KG Inicis CBT CVS: payment currency is not chargeable', [
+                    'order_id' => $orderId,
+                    'tid' => $tid,
+                ]);
+
+                return $this->notifyResult('FAIL', 'failed', 'invalid_payment_currency');
+            }
+
             if ($expectedAmount > 0 && $amount !== $expectedAmount) {
                 $this->storeNotifyHistory($payment, $existingMeta, $payload, 'failed', 'amount_mismatch', $source, $remoteIp);
                 Log::warning('KG Inicis CBT CVS: amount mismatch', [
@@ -251,6 +267,8 @@ class CbtCvsOperationsService
             ]);
 
             return $this->notifyResult('FAIL', 'failed', 'exception');
+        } finally {
+            $this->releaseOrderCallbackLock($callbackLock);
         }
     }
 
@@ -338,6 +356,11 @@ class CbtCvsOperationsService
             return $this->operationError('messages.cbt_cvs.not_waiting_deposit', 422);
         }
 
+        $expectedAmount = $this->resolveExpectedCvsAmount($order, $meta);
+        if ($expectedAmount === null) {
+            return $this->operationError('messages.cbt_cvs.simulate_failed', 422);
+        }
+
         $now = now();
         $payload = [
             'tid' => $payment->transaction_id ?: 'ADMIN_CVS_'.$order->order_number,
@@ -353,7 +376,7 @@ class CbtCvsOperationsService
             'confNo' => (string) ($meta['cvs_conf_no'] ?? ''),
             'receiptNo' => (string) ($meta['cvs_receipt_no'] ?? ''),
             'paymentTerm' => (string) ($meta['cvs_payment_term'] ?? ''),
-            'amount' => (string) $this->resolveExpectedCvsAmount($order, $meta),
+            'amount' => (string) $expectedAmount,
             'currencyCd' => 'JPY',
         ];
 
@@ -599,7 +622,7 @@ class CbtCvsOperationsService
         return $paymentTermAt instanceof CarbonImmutable && $paymentTermAt->isPast();
     }
 
-    private function resolveExpectedCvsAmount(Order $order, array $paymentMeta): int
+    private function resolveExpectedCvsAmount(Order $order, array $paymentMeta): ?int
     {
         $metaAmount = (int) ($paymentMeta['cvs_amount'] ?? 0);
         if ($metaAmount > 0) {
@@ -608,7 +631,9 @@ class CbtCvsOperationsService
 
         // 결제 청구액 SSoT = 결제 통화(order_currency) 환산액 (buildPgPaymentData 와 동일 기준).
         // base≠결제 통화에서 CVS 통보 금액(결제 통화)과 단위가 일치하도록 한다.
-        return app(CurrencyConversionService::class)->resolveOrderPaymentChargeAmount($order);
+        return $this->resolveExpectedPaymentPriceOrNull($order, 'cbt_cvs_notify', [
+            'pay_method' => 'CVS',
+        ]);
     }
 
     private function parseCbtDateTime(?string $value): ?CarbonImmutable
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Concerns/SerializesPaymentCallbacksTest.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Concerns/SerializesPaymentCallbacksTest.php
new file mode 100644
index 00000000..c2a8f52a
--- /dev/null
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Concerns/SerializesPaymentCallbacksTest.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace Plugins\Sirsoft\PayKginicis\Tests\Feature\Concerns;
+
+use Illuminate\Contracts\Cache\LockTimeoutException;
+use Plugins\Sirsoft\PayKginicis\Concerns\SerializesPaymentCallbacks;
+use Plugins\Sirsoft\PayKginicis\Tests\PluginTestCase;
+
+class SerializesPaymentCallbacksTest extends PluginTestCase
+{
+    private object $traitSubject;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->traitSubject = new class {
+            use SerializesPaymentCallbacks {
+                acquireOrderCallbackLock as public;
+                releaseOrderCallbackLock as public;
+                callbackLockKey as public;
+            }
+
+            protected function callbackLockWaitSeconds(): int
+            {
+                return 0;
+            }
+
+            protected function callbackLockTtlSeconds(): int
+            {
+                return 5;
+            }
+        };
+    }
+
+    public function test_same_context_and_order_are_serialized(): void
+    {
+        $orderNumber = 'ORD-KG-LOCK-' . random_int(10000, 99999);
+        $firstLock = $this->traitSubject->acquireOrderCallbackLock('authCallback', $orderNumber);
+
+        try {
+            $this->expectException(LockTimeoutException::class);
+
+            $this->traitSubject->acquireOrderCallbackLock('authCallback', $orderNumber);
+        } finally {
+            $this->traitSubject->releaseOrderCallbackLock($firstLock);
+        }
+    }
+
+    public function test_released_lock_allows_next_callback(): void
+    {
+        $orderNumber = 'ORD-KG-LOCK-' . random_int(10000, 99999);
+        $firstLock = $this->traitSubject->acquireOrderCallbackLock('authCallback', $orderNumber);
+        $this->traitSubject->releaseOrderCallbackLock($firstLock);
+
+        $secondLock = $this->traitSubject->acquireOrderCallbackLock('authCallback', $orderNumber);
+
+        $this->assertNotNull($secondLock);
+        $this->traitSubject->releaseOrderCallbackLock($secondLock);
+    }
+
+    public function test_lock_key_is_scoped_by_context_and_order(): void
+    {
+        $this->assertNotSame(
+            $this->traitSubject->callbackLockKey('authCallback', 'ORD-KG-LOCK-A'),
+            $this->traitSubject->callbackLockKey('vbankNotify', 'ORD-KG-LOCK-A'),
+        );
+
+        $this->assertNotSame(
+            $this->traitSubject->callbackLockKey('authCallback', 'ORD-KG-LOCK-A'),
+            $this->traitSubject->callbackLockKey('authCallback', 'ORD-KG-LOCK-B'),
+        );
+    }
+}
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/AdminCbtTestProductControllerTest.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/AdminCbtTestProductControllerTest.php
index d437e394..22659e74 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/AdminCbtTestProductControllerTest.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/AdminCbtTestProductControllerTest.php
@@ -69,7 +69,7 @@ class AdminCbtTestProductControllerTest extends PluginTestCase
             'order_number' => 'JP-ORDER-ADMIN-CBT-001',
             'order_status' => OrderStatusEnum::PAYMENT_COMPLETE,
             'currency' => 'JPY',
-            'currency_snapshot' => ['JPY' => 1.0],
+            'currency_snapshot' => self::jpyCurrencySnapshot(),
             'subtotal_amount' => 100,
             'total_amount' => 100,
             'total_due_amount' => 100,
@@ -86,7 +86,7 @@ class AdminCbtTestProductControllerTest extends PluginTestCase
             'paid_amount_local' => 100,
             'paid_amount_base' => 100,
             'currency' => 'JPY',
-            'currency_snapshot' => ['JPY' => 1.0],
+            'currency_snapshot' => self::jpyCurrencySnapshot(),
             'payment_meta' => [
                 'is_cbt' => true,
                 'cbt_type' => 'JPPG',
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/CbtPaymentControllerTest.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/CbtPaymentControllerTest.php
index a3158143..cb0d6a8e 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/CbtPaymentControllerTest.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/CbtPaymentControllerTest.php
@@ -1284,6 +1284,7 @@ class CbtPaymentControllerTest extends PluginTestCase
         $order->order_status = OrderStatusEnum::PENDING_ORDER;
         $order->currency = 'JPY';
         $order->total_due_amount = $amount;
+        $order->currency_snapshot = self::jpyCurrencySnapshot();
 
         return $order;
     }
@@ -1294,7 +1295,7 @@ class CbtPaymentControllerTest extends PluginTestCase
             'order_number' => $orderNumber,
             'order_status' => OrderStatusEnum::PENDING_ORDER,
             'currency' => 'JPY',
-            'currency_snapshot' => ['JPY' => 1.0],
+            'currency_snapshot' => self::jpyCurrencySnapshot(),
             'subtotal_amount' => $amount,
             'total_discount_amount' => 0,
             'total_coupon_discount_amount' => 0,
@@ -1328,7 +1329,7 @@ class CbtPaymentControllerTest extends PluginTestCase
             'paid_amount_local' => 0,
             'paid_amount_base' => 0,
             'currency' => 'JPY',
-            'currency_snapshot' => ['JPY' => 1.0],
+            'currency_snapshot' => self::jpyCurrencySnapshot(),
             'paid_at' => null,
         ]);
 
@@ -1369,6 +1370,7 @@ class CbtPaymentControllerTest extends PluginTestCase
             'order_number' => $orderNumber,
             'order_status' => OrderStatusEnum::PENDING_ORDER->value,
             'currency' => 'JPY',
+            'currency_snapshot' => json_encode(self::jpyCurrencySnapshot(), JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES),
             'subtotal_amount' => $amount,
             'total_amount' => $amount,
             'total_tax_amount' => $amount,
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCallbackControllerTest.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCallbackControllerTest.php
index 44994807..5b4475dc 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCallbackControllerTest.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCallbackControllerTest.php
@@ -48,6 +48,8 @@ class PaymentCallbackControllerTest extends PluginTestCase
             'user_id' => $user->id,
             'order_number' => 'ORD-TEST-' . random_int(10000, 99999),
             'order_status' => OrderStatusEnum::PENDING_ORDER,
+            'currency' => 'KRW',
+            'currency_snapshot' => self::krwCurrencySnapshot(),
             'subtotal_amount' => $totalAmount,
             'total_discount_amount' => 0,
             'total_coupon_discount_amount' => 0,
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCloseReportControllerTest.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCloseReportControllerTest.php
index 85dee8e1..8e3fbcb4 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCloseReportControllerTest.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/PaymentCloseReportControllerTest.php
@@ -77,6 +77,30 @@ class PaymentCloseReportControllerTest extends PluginTestCase
             ->assertJsonPath('errors.message.0', 'Payment amount does not match the order amount.');
     }
 
+    public function test_close_report_rejects_unchargeable_payment_currency_without_server_error(): void
+    {
+        $order = $this->makeOrder('ORD-CLOSE-CURRENCY-001', 10000);
+        $order->currency_snapshot = self::unchargeableKrwCurrencySnapshot();
+
+        $orderService = Mockery::mock(OrderProcessingService::class);
+        $orderService->shouldReceive('findByOrderNumber')
+            ->once()
+            ->with('ORD-CLOSE-CURRENCY-001')
+            ->andReturn($order);
+        $orderService->shouldNotReceive('failPayment');
+        $orderService->shouldNotReceive('recordPaymentCancellation');
+
+        $this->app->instance(OrderProcessingService::class, $orderService);
+
+        $response = $this->postJson('/api/plugins/sirsoft-pay_kginicis/payment/close-report', [
+            'oid' => 'ORD-CLOSE-CURRENCY-001',
+            'price' => 10000,
+        ]);
+
+        $response->assertStatus(422)
+            ->assertJsonPath('errors.message.0', 'Payment currency is not chargeable.');
+    }
+
     public function test_close_report_rejects_non_krw_order_without_failing_payment(): void
     {
         $order = $this->makeOrder('ORD-CLOSE-USD-001', 10000, 'USD');
@@ -199,6 +223,7 @@ class PaymentCloseReportControllerTest extends PluginTestCase
             'order_number' => 'ORD-CLOSE-EASYPAY-001',
             'order_status' => OrderStatusEnum::PENDING_ORDER,
             'currency' => 'KRW',
+            'currency_snapshot' => self::krwCurrencySnapshot(),
             'subtotal_amount' => 10000,
             'total_amount' => 10000,
             'total_due_amount' => 10000,
@@ -246,6 +271,7 @@ class PaymentCloseReportControllerTest extends PluginTestCase
         $order->order_status = OrderStatusEnum::PENDING_ORDER;
         $order->currency = $currency;
         $order->total_due_amount = $amount;
+        $order->currency_snapshot = self::currencySnapshotFor($currency);
 
         return $order;
     }
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/SignatureControllerTest.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/SignatureControllerTest.php
index 38cfe35a..1cfd532b 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/SignatureControllerTest.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/SignatureControllerTest.php
@@ -79,6 +79,33 @@ class SignatureControllerTest extends PluginTestCase
             ->assertJsonPath('message', 'Payment amount does not match the order amount.');
     }
 
+    public function test_pc_signature_rejects_unchargeable_payment_currency_without_server_error(): void
+    {
+        $order = $this->makePendingOrder('ORD-SIGN-CURRENCY-001', 10000, 'KRW', self::unchargeableKrwCurrencySnapshot());
+
+        $orderService = Mockery::mock(OrderProcessingService::class);
+        $orderService->shouldReceive('findByOrderNumber')
+            ->with('ORD-SIGN-CURRENCY-001')
+            ->andReturn($order);
+
+        $apiService = Mockery::mock(KgInicisApiService::class);
+        $apiService->shouldNotReceive('hasStandardPaymentCredentials');
+        $apiService->shouldNotReceive('generateSignature');
+        $apiService->shouldNotReceive('generateVerification');
+
+        $this->app->instance(OrderProcessingService::class, $orderService);
+        $this->app->instance(KgInicisApiService::class, $apiService);
+
+        $response = $this->postJson('/api/plugins/sirsoft-pay_kginicis/payment/signature', [
+            'oid' => 'ORD-SIGN-CURRENCY-001',
+            'price' => 10000,
+            'timestamp' => $this->freshEpochMs(),
+        ]);
+
+        $response->assertStatus(422)
+            ->assertJsonPath('message', 'Payment currency is not chargeable.');
+    }
+
     public function test_pc_signature_rejects_non_krw_order(): void
     {
         $order = $this->makePendingOrder('ORD-SIGN-USD-001', 10000, 'USD');
@@ -216,6 +243,32 @@ class SignatureControllerTest extends PluginTestCase
             ->assertJsonPath('message', 'KG Inicis mobile payment credentials are not configured.');
     }
 
+    public function test_mobile_signature_rejects_unchargeable_payment_currency_without_server_error(): void
+    {
+        $order = $this->makePendingOrder('ORD-SIGN-CURRENCY-002', 10000, 'KRW', self::unchargeableKrwCurrencySnapshot());
+
+        $orderService = Mockery::mock(OrderProcessingService::class);
+        $orderService->shouldReceive('findByOrderNumber')
+            ->with('ORD-SIGN-CURRENCY-002')
+            ->andReturn($order);
+
+        $apiService = Mockery::mock(KgInicisApiService::class);
+        $apiService->shouldNotReceive('hasMobilePaymentCredentials');
+        $apiService->shouldNotReceive('generateMobileChkfake');
+
+        $this->app->instance(OrderProcessingService::class, $orderService);
+        $this->app->instance(KgInicisApiService::class, $apiService);
+
+        $response = $this->postJson('/api/plugins/sirsoft-pay_kginicis/payment/mobile/signature', [
+            'oid' => 'ORD-SIGN-CURRENCY-002',
+            'price' => 10000,
+            'timestamp' => $this->freshEpochMs(),
+        ]);
+
+        $response->assertStatus(422)
+            ->assertJsonPath('message', 'Payment currency is not chargeable.');
+    }
+
     public function test_pc_signature_expects_converted_price_for_non_base_order_currency(): void
     {
         // base=USD, 결제통화=KRW. base $6 → KRW 7058 환산이 검증 기준(price)이어야 한다.
@@ -266,7 +319,9 @@ class SignatureControllerTest extends PluginTestCase
         $order->order_status = OrderStatusEnum::PENDING_ORDER;
         $order->currency = $currency;
         $order->total_due_amount = $amount;
-        $order->currency_snapshot = $currencySnapshot;
+        $order->currency_snapshot = $currencySnapshot !== []
+            ? $currencySnapshot
+            : self::currencySnapshotFor($currency);
 
         return $order;
     }
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/VbankNotifyReplayTest.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/VbankNotifyReplayTest.php
index b39e4b60..bdefa05e 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/VbankNotifyReplayTest.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/Feature/Controllers/VbankNotifyReplayTest.php
@@ -39,6 +39,8 @@ class VbankNotifyReplayTest extends PluginTestCase
             'user_id' => $user->id,
             'order_number' => 'ORD-VR-' . random_int(10000, 99999),
             'order_status' => OrderStatusEnum::PAYMENT_COMPLETE,
+            'currency' => 'KRW',
+            'currency_snapshot' => self::krwCurrencySnapshot(),
             'subtotal_amount' => $amount,
             'total_discount_amount' => 0,
             'total_coupon_discount_amount' => 0,
@@ -139,6 +141,8 @@ class VbankNotifyReplayTest extends PluginTestCase
             'user_id' => $user->id,
             'order_number' => 'ORD-FA-' . random_int(10000, 99999),
             'order_status' => OrderStatusEnum::PENDING_ORDER,
+            'currency' => 'KRW',
+            'currency_snapshot' => self::krwCurrencySnapshot(),
             'subtotal_amount' => 30000,
             'total_discount_amount' => 0,
             'total_coupon_discount_amount' => 0,
@@ -203,6 +207,8 @@ class VbankNotifyReplayTest extends PluginTestCase
             'user_id' => User::factory()->create()->id,
             'order_number' => 'ORD-DUP-' . random_int(10000, 99999),
             'order_status' => OrderStatusEnum::PAYMENT_COMPLETE,
+            'currency' => 'KRW',
+            'currency_snapshot' => self::krwCurrencySnapshot(),
             'subtotal_amount' => 20000,
             'total_discount_amount' => 0,
             'total_coupon_discount_amount' => 0,
diff --git a/plugins/_bundled/sirsoft-pay_kginicis/tests/PluginTestCase.php b/plugins/_bundled/sirsoft-pay_kginicis/tests/PluginTestCase.php
index 19b23cc2..c47c2b2b 100644
--- a/plugins/_bundled/sirsoft-pay_kginicis/tests/PluginTestCase.php
+++ b/plugins/_bundled/sirsoft-pay_kginicis/tests/PluginTestCase.php
@@ -62,6 +62,74 @@ abstract class PluginTestCase extends TestCase
         $this->registerEcommerceModuleInManager();
     }
 
+    protected static function krwCurrencySnapshot(): array
+    {
+        return [
+            'base_currency' => 'KRW',
+            'order_currency' => 'KRW',
+            'base_unit' => 1,
+            'exchange_rates' => [
+                'KRW' => [
+                    'rate' => 1,
+                    'rounding_unit' => '1',
+                    'rounding_method' => 'round',
+                    'decimal_places' => 0,
+                    'base_unit' => 1,
+                ],
+            ],
+        ];
+    }
+
+    protected static function jpyCurrencySnapshot(): array
+    {
+        return [
+            'base_currency' => 'JPY',
+            'order_currency' => 'JPY',
+            'base_unit' => 1,
+            'exchange_rates' => [
+                'JPY' => [
+                    'rate' => 1,
+                    'rounding_unit' => '1',
+                    'rounding_method' => 'round',
+                    'decimal_places' => 0,
+                    'base_unit' => 1,
+                ],
+            ],
+        ];
+    }
+
+    protected static function unchargeableKrwCurrencySnapshot(): array
+    {
+        return [
+            'base_currency' => 'USD',
+            'order_currency' => 'KRW',
+            'base_unit' => 1,
+            'exchange_rates' => [
+                'USD' => [
+                    'rate' => 1,
+                    'rounding_unit' => '0.01',
+                    'rounding_method' => 'round',
+                    'decimal_places' => 2,
+                    'base_unit' => 1,
+                ],
+                'KRW' => [
+                    'rate' => 0,
+                    'rounding_unit' => '1',
+                    'rounding_method' => 'round',
+                    'decimal_places' => 0,
+                    'base_unit' => 1,
+                ],
+            ],
+        ];
+    }
+
+    protected static function currencySnapshotFor(string $currency): array
+    {
+        return strtoupper($currency) === 'JPY'
+            ? self::jpyCurrencySnapshot()
+            : self::krwCurrencySnapshot();
+    }
+
     /**
      * 테스트 환경에서 sirsoft-ecommerce 모듈을 ModuleManager 에 명시 등록.
      */