diff --git a/backend-spring/src/main/java/com/erp/service/CommonCodeService.java b/backend-spring/src/main/java/com/erp/service/CommonCodeService.java
index b0dc23e3..6430fbd6 100644
--- a/backend-spring/src/main/java/com/erp/service/CommonCodeService.java
+++ b/backend-spring/src/main/java/com/erp/service/CommonCodeService.java
@@ -53,6 +53,13 @@ public class CommonCodeService extends BaseService {
 
     @Transactional
     public Map<String, Object> insertCodeInfo(Map<String, Object> body, String companyCode, String userId) {
+        Object rawCodeInfo = body.get("code_info");
+        String codeInfo = rawCodeInfo == null ? null : rawCodeInfo.toString().trim();
+        if (codeInfo != null && !codeInfo.isEmpty()
+                && getCodeInfoInfo(codeInfo, companyCode) != null) {
+            throw new IllegalArgumentException("이미 존재하는 그룹 코드입니다: " + codeInfo);
+        }
+
         Map<String, Object> params = new HashMap<>();
         params.put("code_info",     body.get("code_info"));
         params.put("code_name",     body.get("code_name"));