diff --git a/Controllers/CandidateController.cs b/Controllers/CandidateController.cs
index f6852cb..751c6af 100644
--- a/Controllers/CandidateController.cs
+++ b/Controllers/CandidateController.cs
@@ -1559,12 +1559,12 @@ namespace BMA.EHR.Recurit.Exam.Service.Controllers
         }
 
         /// <summary>
-        /// โหลดใบชำระเงิน
+        /// กรอกเลขประจำตัวประชาชน
         /// </summary>
         /// <param name="examId">รหัสรอบสมัคร</param>
         /// <param name="positionId">Id ตำแหน่งสมัครสอบ</param>
         /// <returns></returns>
-        /// <response code="200">เมื่อทำการโหลดใบชำระเงิน สำเร็จ</response>
+        /// <response code="200">เมื่อกรอกเลขประจำตัวประชาชน สำเร็จ</response>
         /// <response code="401">ไม่ได้ Login เข้าระบบ</response>
         /// <response code="500">เมื่อเกิดข้อผิดพลาดในการทำงาน</response>
         [HttpPut("check/citizen/{examId:length(36)}/{positionId:length(36)}")]
diff --git a/Services/CandidateService.cs b/Services/CandidateService.cs
index 8fe7f31..dd90ae6 100644
--- a/Services/CandidateService.cs
+++ b/Services/CandidateService.cs
@@ -2600,64 +2600,42 @@ namespace BMA.EHR.Recurit.Exam.Service.Services
 
         public async Task CheckCitizen(string examId, string positionId, string citizenId)
         {
+            // เช็ครอบสมัครสอบ
             var exam = await _context.PeriodExams.AsQueryable()
                             .Where(p => p.CheckDisability == false)
                             .FirstOrDefaultAsync(x => x.Id == Guid.Parse(examId));
-
             if (exam == null)
                 throw new Exception(GlobalMessages.ExamNotFound);
 
-            #region check digit (old)
-            // if (citizenId.Length != 13)
-            //     throw new Exception(GlobalMessages.CitizenIncomplete);
-
-            // int[] citizenIdDigits = citizenId.Select(c => int.Parse(c.ToString())).ToArray();
-            // int cal =
-            //     citizenIdDigits[0] * 13 +
-            //     citizenIdDigits[1] * 12 +
-            //     citizenIdDigits[2] * 11 +
-            //     citizenIdDigits[3] * 10 +
-            //     citizenIdDigits[4] * 9 +
-            //     citizenIdDigits[5] * 8 +
-            //     citizenIdDigits[6] * 7 +
-            //     citizenIdDigits[7] * 6 +
-            //     citizenIdDigits[8] * 5 +
-            //     citizenIdDigits[9] * 4 +
-            //     citizenIdDigits[10] * 3 +
-            //     citizenIdDigits[11] * 2;
-
-            // int calStp2 = cal % 11;
-            // int chkDigit = 11 - calStp2;
-
-            // if (chkDigit >= 10)
-            // {
-            //     chkDigit = 0;
-            // }
-
-            // if (citizenIdDigits[12] != chkDigit)
-            //     throw new Exception(GlobalMessages.CitizenIncorrect);
-            #endregion
-
+            // เช็คตำแหน่งที่สมัครสอบ
             if (positionId != "00000000-0000-0000-0000-000000000000")
             {
                 var position = await _context.PositionExams.AsQueryable()
-                                .FirstOrDefaultAsync(x => x.Id == Guid.Parse(positionId) && x.PeriodExam == exam);
-
+                            .FirstOrDefaultAsync(x => x.Id == Guid.Parse(positionId) && x.PeriodExam == exam);
                 if (position == null)
                     throw new Exception(GlobalMessages.PositionExamNotFound);
+            } 
+            
+            // เช็คเลขบัตรซ้ำ
+            var candidate = await _context.Candidates.AsQueryable()
+                            .Where(x => 
+                                x.PeriodExam == exam 
+                                && x.UserId != UserId 
+                                && x.CitizenId == citizenId 
+                                && (
+                                    (exam.Fee > 0 && x.Status.Trim().ToUpper() != "REGISTER") 
+                                    || (exam.Fee == 0 && x.Status.Trim().ToUpper() == "CHECKSEAT")
+                                )
+                             )
+                            .FirstOrDefaultAsync();
+            if (candidate != null)
+                throw new Exception(GlobalMessages.CitizanDupicate);
 
-                //var candidate1 = await _context.Candidates.AsQueryable()
-                //                            .Where(x => x.PeriodExam == exam && x.UserId != UserId /*&& x.PositionExam == position*/ && x.CitizenId == citizenId)
-                //                            .FirstOrDefaultAsync();
-                //if (candidate1 != null)
-                //    throw new Exception(GlobalMessages.CitizanDupicate);
-                //return;
-            }
-
+            // เช็ค Digit เลขบัตร
             var apiUrl = $"{_configuration["API"]}/org/dotnet/check-citizen";
             using (var client = new HttpClient())
             {
-                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token.Replace("Bearer ", ""));
+                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token?.Replace("Bearer ", ""));
                 client.DefaultRequestHeaders.Add("api_key", _configuration["API_KEY"]);
                 var _res = await client.PostAsJsonAsync(apiUrl, new
                 {
@@ -2669,12 +2647,6 @@ namespace BMA.EHR.Recurit.Exam.Service.Services
                     throw new Exception(jsonData?["message"]?.ToString());
             }
 
-            var candidate2 = await _context.Candidates.AsQueryable()
-                                       .Where(x => x.PeriodExam == exam && x.UserId != UserId && x.CitizenId == citizenId)
-                                       .FirstOrDefaultAsync();
-            if (candidate2 != null)
-                throw new Exception(GlobalMessages.CitizanDupicate);
-
             return;
         }