diff --git a/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java b/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java
index f6ba81ad..4a1348e3 100644
--- a/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java
+++ b/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java
@@ -41,7 +41,8 @@ public CreateApplicationResponse apply(Long userId, ApplicationRequest request)
 
         Set<Subject> subjects = request.getSubjects();
 
-        validator.ExamDateNotPassed(examIds);
+        validator.examNotFull(examIds);
+        validator.examDateNotPassed(examIds);
         validator.requestNoDuplicateExams(examIds);
         validator.examIdsAndLunchSelection(request.examApplication());
         validator.noDuplicateApplication(userId, examIds);
diff --git a/src/main/java/life/mosu/mosuserver/application/application/vaildator/ApplicationValidator.java b/src/main/java/life/mosu/mosuserver/application/application/vaildator/ApplicationValidator.java
index e94d729d..9a9f81bf 100644
--- a/src/main/java/life/mosu/mosuserver/application/application/vaildator/ApplicationValidator.java
+++ b/src/main/java/life/mosu/mosuserver/application/application/vaildator/ApplicationValidator.java
@@ -3,8 +3,10 @@
 import java.time.LocalDate;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
+import life.mosu.mosuserver.application.exam.cache.ExamQuotaCacheManager;
 import life.mosu.mosuserver.domain.application.ApplicationJpaRepository;
 import life.mosu.mosuserver.domain.exam.ExamJpaEntity;
 import life.mosu.mosuserver.domain.exam.ExamJpaRepository;
@@ -20,6 +22,7 @@ public class ApplicationValidator {
 
     private final ExamJpaRepository examJpaRepository;
     private final ApplicationJpaRepository applicationJpaRepository;
+    private final ExamQuotaCacheManager examQuotaCacheManager;
 
     public void requestNoDuplicateExams(List<Long> examIds) {
         Set<Long> examIdSet = new HashSet<>(examIds);
@@ -30,7 +33,7 @@ public void requestNoDuplicateExams(List<Long> examIds) {
 
     public void examIdsAndLunchSelection(List<ExamApplicationRequest> requests) {
         if (requests == null || requests.isEmpty()) {
-            throw new CustomRuntimeException(ErrorCode.EXAM_APPLICATION_NOT_FOUND);
+            throw new CustomRuntimeException(ErrorCode.EXAM_NOT_FOUND);
         }
 
         List<Long> requestedExamIds = requests.stream()
@@ -68,7 +71,7 @@ public void noDuplicateApplication(Long userId, List<Long> examIds) {
         }
     }
 
-    public void ExamDateNotPassed(List<Long> examIds) {
+    public void examDateNotPassed(List<Long> examIds) {
         List<ExamJpaEntity> exams = examJpaRepository.findAllById(examIds);
         boolean hasPassedExam = exams.stream()
                 .anyMatch(exam -> exam.getExamDate().isBefore(LocalDate.now()));
@@ -77,4 +80,22 @@ public void ExamDateNotPassed(List<Long> examIds) {
             throw new CustomRuntimeException(ErrorCode.EXAM_DATE_PASSED);
         }
     }
+
+    public void examNotFull(List<Long> examIds) {
+        boolean isFull = examIds.stream()
+                .anyMatch(examId -> {
+                    Optional<Long> currentApplications = examQuotaCacheManager.getCurrentApplications(
+                            examId);
+                    Optional<Long> maxCapacity = examQuotaCacheManager.getMaxCapacity(examId);
+
+                    if (currentApplications.isPresent() && maxCapacity.isPresent()) {
+                        return currentApplications.get() >= maxCapacity.get();
+                    }
+                    return false;
+                });
+
+        if (isFull) {
+            throw new CustomRuntimeException(ErrorCode.APPLICATION_CLOSED);
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/life/mosu/mosuserver/application/examapplication/ExamApplicationService.java b/src/main/java/life/mosu/mosuserver/application/examapplication/ExamApplicationService.java
index 6907809c..fef7a1d1 100644
--- a/src/main/java/life/mosu/mosuserver/application/examapplication/ExamApplicationService.java
+++ b/src/main/java/life/mosu/mosuserver/application/examapplication/ExamApplicationService.java
@@ -16,7 +16,6 @@
 import life.mosu.mosuserver.domain.examapplication.projection.ExamApplicationInfoProjection;
 import life.mosu.mosuserver.domain.examapplication.projection.ExamTicketInfoProjection;
 import life.mosu.mosuserver.domain.examapplication.service.ExamNumberGenerationService;
-import life.mosu.mosuserver.domain.payment.PaymentJpaRepository;
 import life.mosu.mosuserver.global.exception.CustomRuntimeException;
 import life.mosu.mosuserver.global.exception.ErrorCode;
 import life.mosu.mosuserver.infra.persistence.s3.S3Service;
@@ -39,7 +38,6 @@ public class ExamApplicationService {
     private final ApplicationJpaRepository applicationJpaRepository;
     private final ExamSubjectJpaRepository examSubjectJpaRepository;
     private final ExamNumberGenerationService examNumberGenerationService;
-    private final PaymentJpaRepository paymentJpaRepository;
     private final S3Service s3Service;
     private final FixedQuantityDiscountCalculator calculator;
 
@@ -122,7 +120,7 @@ public ExamApplicationInfoResponse getApplication(Long userId, Long examApplicat
 //                examApplicationId);
         List<ExamApplicationJpaEntity> examApplicationEntities = examApplicationJpaRepository.findByApplicationId(
                 applicationId);
-        Integer lunchCount = (int) examApplicationEntities.stream()
+        int lunchCount = (int) examApplicationEntities.stream()
                 .filter(ExamApplicationJpaEntity::getIsLunchChecked)
                 .count();
 
@@ -173,8 +171,11 @@ private void validateUser(Long userId, Long examApplicationId) {
     }
 
     private int getAppliedDiscountAmount(Integer totalAmount) {
-        log.info("total amount: {}", totalAmount);
-        return calculator.getAppliedDiscountAmount(totalAmount);
+        try {
+            return calculator.getAppliedDiscountAmount(totalAmount);
+        } catch (Exception ex) {
+            throw new CustomRuntimeException(ErrorCode.PRICE_LOAD_FAILURE);
+        }
     }
 
     private void validateExamTicketOpenDate(LocalDate examDate, String examNumber) {
diff --git a/src/main/java/life/mosu/mosuserver/domain/refund/RefundJpaRepository.java b/src/main/java/life/mosu/mosuserver/domain/refund/RefundJpaRepository.java
index 6a11db71..a10d64e3 100644
--- a/src/main/java/life/mosu/mosuserver/domain/refund/RefundJpaRepository.java
+++ b/src/main/java/life/mosu/mosuserver/domain/refund/RefundJpaRepository.java
@@ -26,7 +26,7 @@ public interface RefundJpaRepository extends JpaRepository<RefundJpaEntity, Long
                 JOIN ExamApplicationJpaEntity ea ON r.examApplicationId = ea.id
                 JOIN ExamJpaEntity e ON ea.examId = e.id
                 WHERE r.examApplicationId = :examApplicationId
-                AND p.paymentStatus = 'CANCELLED_DONE'
+                AND r.refundStatus = 'DONE'
             """)
     Optional<RefundNotifyProjection> findRefundByExamApplicationId(
             @Param("examApplicationId") Long examApplicationId);
diff --git a/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java b/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java
index 665b6071..93ca1f5a 100644
--- a/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java
+++ b/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java
@@ -64,6 +64,9 @@ public enum ErrorCode {
     APPLICATION_SCHOOL_DUPLICATED(HttpStatus.BAD_REQUEST, "동일 일자의 같은 학교를 신청할 수 없습니다."),
     EXAM_DUPLICATED(HttpStatus.BAD_REQUEST, "동일한 시험을 신청할 수 없습니다."),
     WRONG_APPLICATION_ID_TYPE(HttpStatus.BAD_REQUEST, "신청 ID 타입이 올바르지 않습니다."),
+    PRICE_LOAD_FAILURE(HttpStatus.CONFLICT, "신청 가격 정보를 가져오는데 실패했습니다."),
+    APPLICATION_CLOSED(HttpStatus.BAD_REQUEST, "신청이 마감되었습니다."),
+
     // 프로필 관련 에러
     PROFILE_ALREADY_EXISTS(HttpStatus.CONFLICT, "프로필이 이미 존재합니다."),
     PROFILE_NOT_FOUND(HttpStatus.NOT_FOUND, "프로필을 찾을 수 없습니다."),
@@ -149,6 +152,8 @@ public enum ErrorCode {
 
     //LUA 관련
     LUA_SCRIPT_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "LUA 스크립트 실행 중 오류가 발생했습니다.");
+
+
     private final HttpStatus status;
     private final String message;
 }