diff --git a/roome/src/main/java/com/roome/domain/payment/service/TossPaymentClient.java b/roome/src/main/java/com/roome/domain/payment/service/TossPaymentClient.java
index 97fa9d4c..cc8f4245 100644
--- a/roome/src/main/java/com/roome/domain/payment/service/TossPaymentClient.java
+++ b/roome/src/main/java/com/roome/domain/payment/service/TossPaymentClient.java
@@ -13,6 +13,7 @@
 import org.springframework.http.*;
 import org.springframework.stereotype.Component;
 import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.HttpStatusCodeException;
 import org.springframework.web.client.RestTemplate;
 
 import java.io.IOException;
@@ -61,18 +62,45 @@ public ResponseEntity<String> requestConfirm(PaymentVerifyDto verifyDto) {
 
         HttpEntity<Map<String, Object>> requestEntity = new HttpEntity<>(requestBody, headers);
 
-        // ✅ RestTemplate을 사용하여 POST 요청 수행
-        ResponseEntity<String> response = restTemplate.exchange(
-                requestUrl, HttpMethod.POST, requestEntity, String.class
-        );
-
-        log.info("Toss API 응답 - Status: {}, Headers: {}, Body: {}",
-                response.getStatusCode(), response.getHeaders(), response.getBody());
-
+        try {
+            ResponseEntity<String> response = restTemplate.exchange(
+                    requestUrl, HttpMethod.POST, requestEntity, String.class
+            );
+            log.info("Toss 결제 승인 응답 - Status: {}", response.getStatusCode());
+            return response;
+        } catch (HttpStatusCodeException e) {
+            // Toss는 실패 시 응답 body에 {code, message}를 담아 주니까 이걸 파싱해 도메인 에러로 매핑
+            throw mapConfirmError(e);
+        }
+    }
 
-        log.info("Toss 결제 승인 응답 - Status: {}, Body: {}", response.getStatusCode(), response.getBody());
+    // Toss 승인 실패 응답의 error code를 도메인 에러로 매핑
+    // 알려진 코드만 세분화하고, 나머지는 일반 실패로 두되 실제 code와 message를 로그로 남김
+    private BusinessException mapConfirmError(HttpStatusCodeException e) {
+        String code = null;
+        String message = null;
+        try {
+            JsonNode body = objectMapper.readTree(e.getResponseBodyAsString());
+            code = body.path("code").asText(null);
+            message = body.path("message").asText(null);
+        } catch (Exception parseError) {
+            log.warn("Toss 오류 응답 파싱 실패: body={}", e.getResponseBodyAsString());
+        }
 
-        return response;
+        log.error("Toss 결제 승인 실패: httpStatus={}, code={}, message={}",
+                e.getStatusCode(), code, message);
+
+        ErrorCode mapped = switch (code == null ? "" : code) {
+            // 이미 승인 처리된 결제 (재시도/중복 요청)
+            case "ALREADY_PROCESSED_PAYMENT" -> ErrorCode.PAYMENT_ALREADY_PROCESSED;
+            // 카드사/결제 수단 거절 (사용자 조치 필요)
+            case "REJECT_CARD_COMPANY", "REJECT_ACCOUNT_PAYMENT", "INVALID_STOPPED_CARD",
+                 "EXCEED_MAX_DAILY_PAYMENT_COUNT", "NOT_ENOUGH_BALANCE",
+                 "INVALID_CARD_EXPIRATION", "EXCEED_MAX_PAYMENT_AMOUNT" -> ErrorCode.PAYMENT_REJECTED;
+            // 그 외: 실제 code는 로그로 남기고 일반 실패로 처리
+            default -> ErrorCode.PAYMENT_VERIFICATION_FAILED;
+        };
+        return new BusinessException(mapped);
     }
 
 
diff --git a/roome/src/main/java/com/roome/global/exception/ErrorCode.java b/roome/src/main/java/com/roome/global/exception/ErrorCode.java
index f9e7869b..c087d1d3 100644
--- a/roome/src/main/java/com/roome/global/exception/ErrorCode.java
+++ b/roome/src/main/java/com/roome/global/exception/ErrorCode.java
@@ -63,6 +63,7 @@ public enum ErrorCode {
   PAYMENT_NOT_FOUND(HttpStatus.NOT_FOUND, "해당 결제 정보를 찾을 수 없습니다."),
   PAYMENT_AMOUNT_MISMATCH(HttpStatus.BAD_REQUEST, "결제 금액이 일치하지 않습니다."),
   PAYMENT_VERIFICATION_FAILED(HttpStatus.BAD_REQUEST, "결제 검증에 실패했습니다."),
+  PAYMENT_REJECTED(HttpStatus.BAD_REQUEST, "카드사/결제 수단에서 결제가 거절되었습니다."),
   PAYMENT_PROCESSING_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "결제 처리 중 오류가 발생했습니다."),
   PAYMENT_ACCESS_DENIED(HttpStatus.FORBIDDEN, "해당 결제에 대한 접근 권한이 없습니다."),
   PAYMENT_NOT_CANCELABLE(HttpStatus.BAD_REQUEST, "이 결제는 취소할 수 없습니다."),
diff --git a/roome/src/test/java/com/roome/domain/payment/service/TossPaymentClientTest.java b/roome/src/test/java/com/roome/domain/payment/service/TossPaymentClientTest.java
index 2e920f83..8fa78891 100644
--- a/roome/src/test/java/com/roome/domain/payment/service/TossPaymentClientTest.java
+++ b/roome/src/test/java/com/roome/domain/payment/service/TossPaymentClientTest.java
@@ -1,6 +1,10 @@
 package com.roome.domain.payment.service;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.roome.domain.payment.dto.PaymentVerifyDto;
+import com.roome.global.exception.BusinessException;
+import com.roome.global.exception.ErrorCode;
+import java.nio.charset.StandardCharsets;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -34,6 +38,43 @@ void setUp() {
         ReflectionTestUtils.setField(tossPaymentClient, "secretKey", testSecretKey);
     }
 
+    @Test
+    @DisplayName("Toss 승인 실패 - ALREADY_PROCESSED_PAYMENT는 PAYMENT_ALREADY_PROCESSED로 매핑된다.")
+    void requestConfirm_AlreadyProcessed_Mapped() throws Exception {
+        BusinessException thrown = assertConfirmErrorMapped(
+                "{\"code\":\"ALREADY_PROCESSED_PAYMENT\",\"message\":\"이미 처리된 결제 입니다.\"}");
+        assertEquals(ErrorCode.PAYMENT_ALREADY_PROCESSED, thrown.getErrorCode());
+    }
+
+    @Test
+    @DisplayName("Toss 승인 실패 - 카드 거절 코드는 PAYMENT_REJECTED로 매핑된다.")
+    void requestConfirm_CardRejected_Mapped() throws Exception {
+        BusinessException thrown = assertConfirmErrorMapped(
+                "{\"code\":\"REJECT_CARD_COMPANY\",\"message\":\"카드사에서 승인을 거절했습니다.\"}");
+        assertEquals(ErrorCode.PAYMENT_REJECTED, thrown.getErrorCode());
+    }
+
+    @Test
+    @DisplayName("Toss 승인 실패 - 알 수 없는 코드는 일반 실패(PAYMENT_VERIFICATION_FAILED)로 매핑된다.")
+    void requestConfirm_UnknownCode_FallsBack() throws Exception {
+        BusinessException thrown = assertConfirmErrorMapped(
+                "{\"code\":\"SOME_NEW_CODE\",\"message\":\"알 수 없는 오류\"}");
+        assertEquals(ErrorCode.PAYMENT_VERIFICATION_FAILED, thrown.getErrorCode());
+    }
+
+    // Toss가 4xx 오류 body를 반환하는 상황을 구성하고, requestConfirm이 던지는 BusinessException을 돌려준다.
+    private BusinessException assertConfirmErrorMapped(String errorBody) throws Exception {
+        HttpClientErrorException httpError = HttpClientErrorException.create(
+                HttpStatus.BAD_REQUEST, "Bad Request", HttpHeaders.EMPTY,
+                errorBody.getBytes(StandardCharsets.UTF_8), StandardCharsets.UTF_8);
+        when(restTemplate.exchange(anyString(), eq(HttpMethod.POST), any(HttpEntity.class), eq(String.class)))
+                .thenThrow(httpError);
+        when(objectMapper.readTree(errorBody)).thenReturn(new ObjectMapper().readTree(errorBody));
+
+        return assertThrows(BusinessException.class,
+                () -> tossPaymentClient.requestConfirm(new PaymentVerifyDto("pk123", "order123", 5000)));
+    }
+
     @Test
     @DisplayName("orderId 결제 조회 성공 - 응답 파싱")
     void findPaymentByOrderId_Success() throws Exception {