diff --git a/back/src/wos/wos.service.ts b/back/src/wos/wos.service.ts
index 095f892..470a62f 100644
--- a/back/src/wos/wos.service.ts
+++ b/back/src/wos/wos.service.ts
@@ -148,6 +148,10 @@ export class WosService {
         if (attempt < maxRetries) continue;
         return { success: false, message: `캡차 인식 실패 (${maxRetries}회 시도)`, err_code: data.err_code };
       }
+      if (data.code !== 0 && (data.err_code === 0 || data.msg === 'Sign Error')) {
+        if (attempt < maxRetries) continue;
+        return { success: false, message: 'Sign Error (캡차 오인식)', err_code: data.err_code };
+      }
       return { success: false, message: data.msg || `실패 (${data.err_code})`, err_code: data.err_code };
     }
 
@@ -180,7 +184,7 @@ export class WosService {
         result = { success: false, message: err.message || '오류 발생' };
       }
 
-      if (result.err_code === 40008 || result.err_code === 40011) {
+      if (result.err_code === 40008 || result.err_code === 40011 || result.err_code === 40005) {
         result = { success: true, message: ALREADY_MSG, err_code: result.err_code };
       }
 
@@ -270,7 +274,7 @@ export class WosService {
         const result = await this.redeemOne(user.fid, code);
 
         const finalResult =
-          result.err_code === 40008 || result.err_code === 40011
+          result.err_code === 40008 || result.err_code === 40011 || result.err_code === 40005
             ? { success: true, message: ALREADY_MSG }
             : result;