diff --git a/BusinessLogging.cs b/BusinessLogging.cs
index bd26917..e7b822d 100644
--- a/BusinessLogging.cs
+++ b/BusinessLogging.cs
@@ -54,6 +54,7 @@ internal enum BizChannel
     Attendance,
     UserSync,
     Template,
+    DepartmentalSync,
     Unreachable
 }
 
diff --git a/DeviceSettings.config b/DeviceSettings.config
index 9cf6d02..b7a9bf3 100644
--- a/DeviceSettings.config
+++ b/DeviceSettings.config
@@ -7,7 +7,7 @@
 "EnableTemplateDeviceToDbSync": false,
 "EnableTemplateDbToDeviceSync": false,
 
-"SourceMachineIp": "",
+"SourceMachineIp": "192.168.91.80",
 "TargetMachineIps": [
 "192.168.91.80"
 ],
@@ -15,11 +15,10 @@
 "SyncEmployeeIds": [],
 "SyncDepartmentIds": [],
 
-"EnableInitialDepartmentSync": true,
-"InitialSyncDepartmentIds": [
-"357"
-],
+"EnableInitialDepartmentSync": false,
+"InitialSyncDepartmentIds": [],
 "InitialSyncEmployeeIds": [],
+"InitialSyncLocationSiteId": 2,
 "EnableEmployeePhotoSource": true,
 "EmployeePhotoBaseUrl": "https://portal.utopiaindustries.pk/uind/employee-photo/"
 }
diff --git a/HikvisionAttendanceManager.InitialSync.cs b/HikvisionAttendanceManager.InitialSync.cs
index ded0f14..515933a 100644
--- a/HikvisionAttendanceManager.InitialSync.cs
+++ b/HikvisionAttendanceManager.InitialSync.cs
@@ -27,21 +27,39 @@ internal sealed partial class HikvisionAttendanceManager
 
         ct.ThrowIfCancellationRequested();
 
+        if (!_config.InitialSyncLocationSiteId.HasValue ||
+            _config.InitialSyncLocationSiteId.Value <= 0)
+        {
+            const string reason =
+                "InitialSyncLocationSiteId is not configured; Initial Department Sync requires an explicit location-site filter.";
+            _logger.OpsWarn("INITIAL_SYNC", "skipped — " + reason);
+            _logger.Biz(BizChannel.DepartmentalSync,
+                "DEPARTMENTAL SYNC FAILED",
+                "",
+                "Reason : " + reason,
+                "");
+            _logger.BizSeparator(BizChannel.DepartmentalSync);
+            return;
+        }
+        var locationSiteId = _config.InitialSyncLocationSiteId.Value;
+
         var deptIds = (_config.InitialSyncDepartmentIds ?? new List<string>())
             .Where(x => !string.IsNullOrWhiteSpace(x))
             .Select(x => x.Trim())
             .Distinct(StringComparer.OrdinalIgnoreCase)
             .ToList();
-        if (deptIds.Count == 0)
-        {
-            _logger.OpsWarn("INITIAL_SYNC", "skipped — InitialSyncDepartmentIds is empty");
-            return;
-        }
+        var allActiveDepartmentsMode = deptIds.Count == 0;
 
         var targets = ResolveInitialSyncTargets();
         if (targets.Count == 0)
         {
             _logger.OpsWarn("INITIAL_SYNC", "skipped — no valid TargetMachineIps");
+            _logger.Biz(BizChannel.DepartmentalSync,
+                "DEPARTMENTAL SYNC FAILED",
+                "",
+                "Reason : No valid target machines are configured.",
+                "");
+            _logger.BizSeparator(BizChannel.DepartmentalSync);
             return;
         }
 
@@ -51,22 +69,33 @@ internal sealed partial class HikvisionAttendanceManager
             .Distinct(StringComparer.OrdinalIgnoreCase)
             .ToList();
 
-        var employees = LoadEmployeesForInitialDepartmentSync(deptIds, employeeIdFilter, out var loadErr);
+        if (allActiveDepartmentsMode && employeeIdFilter.Count > 0)
+        {
+            _logger.OpsWarn("INITIAL_SYNC",
+                "InitialSyncEmployeeIds ignored because InitialSyncDepartmentIds is empty; " +
+                "mode=ALL_ACTIVE_DEPARTMENTS_AND_EMPLOYEES");
+            employeeIdFilter.Clear();
+        }
+
+        var selection = LoadEmployeesForInitialDepartmentSync(
+            deptIds,
+            employeeIdFilter,
+            locationSiteId,
+            out var loadErr);
         if (!string.IsNullOrWhiteSpace(loadErr))
+        {
             _logger.Warn("INITIAL_SYNC: employee lookup failed err=" + loadErr);
-
-        if (employeeIdFilter.Count > 0)
-            _logger.Ops("INITIAL_SYNC", "Employee filter: departmentIds=" + string.Join(",", deptIds) +
-                " allowListCount=" + employeeIdFilter.Count +
-                " allowList=" + string.Join(",", employeeIdFilter) +
-                " matched=" + employees.Count);
-
-        _logger.Ops("INITIAL_SYNC", "departmentIds=" + string.Join(",", deptIds) +
-            " employeeFilter=" + (employeeIdFilter.Count > 0 ? "selective(" + employeeIdFilter.Count + ")" : "whole-department") +
-            " employeesFound=" + employees.Count);
-
-        if (employees.Count == 0)
+            _logger.Biz(BizChannel.DepartmentalSync,
+                "DEPARTMENTAL SYNC FAILED",
+                "",
+                "Reason : " + loadErr,
+                "");
+            _logger.BizSeparator(BizChannel.DepartmentalSync);
             return;
+        }
+
+        LogInitialDepartmentSelection(deptIds, employeeIdFilter, selection);
+        var employees = selection.Employees;
 
         var maxRetries = Math.Max(1, SyncPol.HttpMaxRetries);
         var photoBase = (_config.EmployeePhotoBaseUrl ?? "").Trim();
@@ -90,6 +119,12 @@ internal sealed partial class HikvisionAttendanceManager
                     "Machine is not connected.",
                     "");
                 _logger.BizSeparator(BizChannel.UserSync);
+                WriteDepartmentalSyncSummary(
+                    target,
+                    selection,
+                    employeeIdFilter,
+                    false,
+                    Array.Empty<InitialSyncEmployeeOutcome>());
                 continue;
             }
 
@@ -97,9 +132,22 @@ internal sealed partial class HikvisionAttendanceManager
                 "MACHINE " + (target.DeviceId ?? "") + " -> Total Users : " + employees.Count,
                 "");
 
+            if (employees.Count == 0)
+            {
+                WriteDepartmentalSyncSummary(
+                    target,
+                    selection,
+                    employeeIdFilter,
+                    true,
+                    Array.Empty<InitialSyncEmployeeOutcome>());
+                _logger.BizSeparator(BizChannel.UserSync);
+                continue;
+            }
+
             var existing = FetchAllUsersIsapiForSync(target, maxRetries, ct);
             var existingNos = new HashSet<string>(existing.Select(u => u.EmployeeNo), StringComparer.OrdinalIgnoreCase);
             var faceRejectedEmployees = new List<(string EmployeeNo, string Reason)>();
+            var employeeOutcomes = new List<InitialSyncEmployeeOutcome>();
 
             foreach (var emp in employees)
             {
@@ -186,6 +234,15 @@ internal sealed partial class HikvisionAttendanceManager
                 }
                 finally
                 {
+                    employeeOutcomes.Add(new InitialSyncEmployeeOutcome
+                    {
+                        DepartmentId = emp.DepartmentId,
+                        EmployeeNo = employeeNo,
+                        Synced = faceUploaded,
+                        Reason = faceUploaded
+                            ? ""
+                            : (string.IsNullOrWhiteSpace(reason) ? "face_upload_failed" : reason)
+                    });
                     WriteInitialSyncEmployeeBizLog(target, employeeNo, userCreated, faceUploaded, reason);
 
                     if (photoDownloaded && faceUploaded)
@@ -222,6 +279,7 @@ internal sealed partial class HikvisionAttendanceManager
             }
 
             WriteFaceRejectedEmployeeSummary("INITIAL_SYNC", target, faceRejectedEmployees);
+            WriteDepartmentalSyncSummary(target, selection, employeeIdFilter, true, employeeOutcomes);
             _logger.BizSeparator(BizChannel.UserSync);
         }
     }
@@ -356,15 +414,14 @@ internal sealed partial class HikvisionAttendanceManager
         return targets;
     }
 
-    private List<InitialSyncEmployee> LoadEmployeesForInitialDepartmentSync(
+    private InitialSyncSelection LoadEmployeesForInitialDepartmentSync(
         IReadOnlyList<string> departmentIds,
         IReadOnlyList<string> employeeIdAllowList,
+        int locationSiteId,
         out string error)
     {
         error = "";
-        var result = new List<InitialSyncEmployee>();
-        if (departmentIds == null || departmentIds.Count == 0)
-            return result;
+        var result = new InitialSyncSelection { LocationSiteId = locationSiteId };
         if (!_config.EnableDbIntegration || _dbConnectionFactory == null)
         {
             error = "DB integration not available for initial department sync.";
@@ -374,54 +431,131 @@ internal sealed partial class HikvisionAttendanceManager
         if (!_dbConnectionFactory.TryBuildConnectionString(out var cs, out error))
             return result;
 
-        var hasAllowList = employeeIdAllowList != null && employeeIdAllowList.Count > 0;
+        var hasDepartmentFilter = departmentIds != null && departmentIds.Count > 0;
+        var hasAllowList = hasDepartmentFilter &&
+            employeeIdAllowList != null &&
+            employeeIdAllowList.Count > 0;
 
         try
         {
             using var conn = new MySqlConnection(cs);
             conn.Open();
-            var sql = new StringBuilder("SELECT id, serial_number FROM employee WHERE department_id IN (");
-            for (int i = 0; i < departmentIds.Count; i++)
-            {
-                if (i > 0) sql.Append(',');
-                sql.Append("@d").Append(i);
-            }
-            sql.Append(')');
 
-            if (hasAllowList)
+            if (hasDepartmentFilter)
             {
-                sql.Append(" AND serial_number IN (");
-                for (int i = 0; i < employeeIdAllowList.Count; i++)
+                var departmentSql = new StringBuilder(
+                    "SELECT id, is_active FROM department WHERE id IN (");
+                AppendSqlParameters(departmentSql, "@d", departmentIds.Count);
+                departmentSql.Append(')');
+
+                using var departmentCmd = new MySqlCommand(departmentSql.ToString(), conn);
+                AddSqlParameters(departmentCmd, "@d", departmentIds);
+                var foundDepartmentIds = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+                using (var departmentReader = departmentCmd.ExecuteReader())
                 {
-                    if (i > 0) sql.Append(',');
-                    sql.Append("@e").Append(i);
+                    while (departmentReader.Read())
+                    {
+                        var departmentId = departmentReader["id"]?.ToString()?.Trim() ?? "";
+                        if (departmentId.Length == 0)
+                            continue;
+
+                        foundDepartmentIds.Add(departmentId);
+                        if (IsDatabaseActive(departmentReader["is_active"]))
+                            result.ActiveDepartmentIds.Add(departmentId);
+                        else
+                            result.InactiveDepartmentIds.Add(departmentId);
+                    }
                 }
-                sql.Append(')');
+
+                foreach (var requestedId in departmentIds)
+                {
+                    if (!foundDepartmentIds.Contains(requestedId))
+                        result.MissingDepartmentIds.Add(requestedId);
+                }
+            }
+            else
+            {
+                using var departmentCmd = new MySqlCommand(
+                    "SELECT id FROM department WHERE is_active = 1", conn);
+                using (var departmentReader = departmentCmd.ExecuteReader())
+                {
+                    while (departmentReader.Read())
+                    {
+                        var departmentId = departmentReader["id"]?.ToString()?.Trim() ?? "";
+                        if (departmentId.Length > 0)
+                            result.ActiveDepartmentIds.Add(departmentId);
+                    }
+                }
+
+                using var inactiveDepartmentCmd = new MySqlCommand(
+                    "SELECT COUNT(*) FROM department WHERE is_active IS NULL OR is_active <> 1", conn);
+                result.InactiveDepartmentCount = Convert.ToInt32(inactiveDepartmentCmd.ExecuteScalar() ?? 0);
             }
 
-            using var cmd = new MySqlCommand(sql.ToString(), conn);
-            for (int i = 0; i < departmentIds.Count; i++)
-                cmd.Parameters.AddWithValue("@d" + i, departmentIds[i]);
+            if (result.ActiveDepartmentIds.Count == 0)
+                return result;
+
+            var employeeSql = new StringBuilder(
+                "SELECT e.id, e.serial_number, e.department_id " +
+                "FROM employee e " +
+                "INNER JOIN department d ON d.id = e.department_id " +
+                "WHERE d.is_active = 1 AND e.is_active = 1 " +
+                "AND e.location_site_id = @locationSiteId AND e.department_id IN (");
+            AppendSqlParameters(employeeSql, "@activeDept", result.ActiveDepartmentIds.Count);
+            employeeSql.Append(')');
             if (hasAllowList)
             {
-                for (int i = 0; i < employeeIdAllowList.Count; i++)
-                    cmd.Parameters.AddWithValue("@e" + i, employeeIdAllowList[i]);
+                employeeSql.Append(" AND e.serial_number IN (");
+                AppendSqlParameters(employeeSql, "@e", employeeIdAllowList.Count);
+                employeeSql.Append(')');
             }
 
-            using var rd = cmd.ExecuteReader();
+            using var cmd = new MySqlCommand(employeeSql.ToString(), conn);
+            cmd.Parameters.AddWithValue("@locationSiteId", locationSiteId);
+            AddSqlParameters(cmd, "@activeDept", result.ActiveDepartmentIds);
+            if (hasAllowList)
+                AddSqlParameters(cmd, "@e", employeeIdAllowList);
+
             var seenSerial = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
-            while (rd.Read())
+            using (var rd = cmd.ExecuteReader())
             {
-                var serial = rd["serial_number"]?.ToString()?.Trim() ?? "";
-                if (serial.Length == 0 || !seenSerial.Add(serial))
-                    continue;
-                result.Add(new InitialSyncEmployee
+                while (rd.Read())
                 {
-                    Id = rd["id"]?.ToString()?.Trim() ?? "",
-                    SerialNumber = serial,
-                    Name = ""
-                });
+                    var serial = rd["serial_number"]?.ToString()?.Trim() ?? "";
+                    if (serial.Length == 0 || !seenSerial.Add(serial))
+                        continue;
+                    result.Employees.Add(new InitialSyncEmployee
+                    {
+                        Id = rd["id"]?.ToString()?.Trim() ?? "",
+                        SerialNumber = serial,
+                        DepartmentId = rd["department_id"]?.ToString()?.Trim() ?? "",
+                        Name = ""
+                    });
+                }
             }
+
+            var inactiveEmployeeSql = new StringBuilder(
+                "SELECT COUNT(*) " +
+                "FROM employee e " +
+                "INNER JOIN department d ON d.id = e.department_id " +
+                "WHERE d.is_active = 1 AND (e.is_active IS NULL OR e.is_active <> 1) " +
+                "AND e.location_site_id = @inactiveLocationSiteId AND e.department_id IN (");
+            AppendSqlParameters(inactiveEmployeeSql, "@inactiveDept", result.ActiveDepartmentIds.Count);
+            inactiveEmployeeSql.Append(')');
+            if (hasAllowList)
+            {
+                inactiveEmployeeSql.Append(" AND e.serial_number IN (");
+                AppendSqlParameters(inactiveEmployeeSql, "@inactiveEmp", employeeIdAllowList.Count);
+                inactiveEmployeeSql.Append(')');
+            }
+
+            using var inactiveEmployeeCmd = new MySqlCommand(inactiveEmployeeSql.ToString(), conn);
+            inactiveEmployeeCmd.Parameters.AddWithValue("@inactiveLocationSiteId", locationSiteId);
+            AddSqlParameters(inactiveEmployeeCmd, "@inactiveDept", result.ActiveDepartmentIds);
+            if (hasAllowList)
+                AddSqlParameters(inactiveEmployeeCmd, "@inactiveEmp", employeeIdAllowList);
+            result.SkippedInactiveEmployeeCount =
+                Convert.ToInt32(inactiveEmployeeCmd.ExecuteScalar() ?? 0);
         }
         catch (Exception ex)
         {
@@ -431,6 +565,212 @@ internal sealed partial class HikvisionAttendanceManager
         return result;
     }
 
+    private void LogInitialDepartmentSelection(
+        IReadOnlyList<string> requestedDepartmentIds,
+        IReadOnlyList<string> employeeIdAllowList,
+        InitialSyncSelection selection)
+    {
+        var allDepartments = requestedDepartmentIds == null || requestedDepartmentIds.Count == 0;
+        var selectiveEmployees = !allDepartments &&
+            employeeIdAllowList != null &&
+            employeeIdAllowList.Count > 0;
+        var inactiveCount = allDepartments
+            ? selection.InactiveDepartmentCount
+            : selection.InactiveDepartmentIds.Count;
+
+        _logger.Ops("INITIAL_SYNC",
+            "InitialSyncLocationSiteId=" + selection.LocationSiteId +
+            " departmentMode=" + (allDepartments ? "ALL_ACTIVE" : "SELECTED") +
+            " selectedDepartmentCount=" + (allDepartments
+                ? selection.ActiveDepartmentIds.Count
+                : requestedDepartmentIds.Count) +
+            " activeDepartmentCount=" + selection.ActiveDepartmentIds.Count +
+            " inactiveDepartmentCount=" + inactiveCount +
+            " activeDepartments=" + FormatLogValues(selection.ActiveDepartmentIds) +
+            " inactiveDepartments=" + (allDepartments
+                ? "(all inactive departments excluded)"
+                : FormatLogValues(selection.InactiveDepartmentIds)) +
+            " missingDepartments=" + FormatLogValues(selection.MissingDepartmentIds));
+
+        _logger.Ops("INITIAL_SYNC",
+            "employeeFilterMode=" + (selectiveEmployees ? "SELECTIVE" : "ALL") +
+            (selectiveEmployees
+                ? " allowListCount=" + employeeIdAllowList.Count +
+                  " allowList=" + FormatLogValues(employeeIdAllowList)
+                : "") +
+            " finalEmployeeCount=" + selection.Employees.Count +
+            " skippedInactiveEmployees=" + selection.SkippedInactiveEmployeeCount);
+    }
+
+    private void WriteDepartmentalSyncSummary(
+        HikvisionAttendanceWindowsService.DeviceConfig target,
+        InitialSyncSelection selection,
+        IReadOnlyList<string> employeeIdAllowList,
+        bool targetOnline,
+        IReadOnlyList<InitialSyncEmployeeOutcome> outcomes)
+    {
+        var lines = new List<string>
+        {
+            "DEPARTMENTAL SYNC SUMMARY",
+            "",
+            "Machine ID : " + (target.DeviceId ?? ""),
+            "Machine IP : " + (target.Ip ?? ""),
+            "InitialSyncLocationSiteId : " + selection.LocationSiteId,
+            "Employee Filter : " + (employeeIdAllowList.Count > 0 ? "SELECTIVE" : "ALL"),
+            "Active Departments : " + selection.ActiveDepartmentIds.Count,
+            "Inactive Departments Skipped : " +
+                (selection.InactiveDepartmentIds.Count + selection.InactiveDepartmentCount),
+            "Eligible Active Employees : " + selection.Employees.Count,
+            "Skipped Inactive Employees : " + selection.SkippedInactiveEmployeeCount,
+            ""
+        };
+
+        foreach (var departmentId in selection.ActiveDepartmentIds
+                     .OrderBy(x => x, StringComparer.OrdinalIgnoreCase))
+        {
+            var eligibleCount = selection.Employees.Count(x =>
+                string.Equals(x.DepartmentId, departmentId, StringComparison.OrdinalIgnoreCase));
+            var departmentOutcomes = outcomes.Where(x =>
+                string.Equals(x.DepartmentId, departmentId, StringComparison.OrdinalIgnoreCase)).ToList();
+            var syncedCount = departmentOutcomes.Count(x => x.Synced);
+            var failedCount = Math.Max(0, eligibleCount - syncedCount);
+
+            string status;
+            string reason = "";
+            if (!targetOnline)
+            {
+                status = "NOT SYNCED";
+                reason = "Target machine is offline.";
+            }
+            else if (eligibleCount == 0)
+            {
+                status = "NOT SYNCED";
+                reason = employeeIdAllowList.Count > 0
+                    ? "No selected active employees belong to this active department."
+                    : "Department has no active employees.";
+            }
+            else if (syncedCount == eligibleCount)
+            {
+                status = "SYNCED";
+            }
+            else if (syncedCount > 0)
+            {
+                status = "PARTIALLY SYNCED";
+            }
+            else
+            {
+                status = "NOT SYNCED";
+            }
+
+            lines.Add("Department " + departmentId + " : " + status);
+            lines.Add("Eligible Users : " + eligibleCount);
+            lines.Add("Synced Users : " + syncedCount);
+            lines.Add("Failed Users : " + failedCount);
+            if (failedCount > 0)
+                lines.Add("Failed Employee Numbers : " +
+                    string.Join(",", targetOnline
+                        ? departmentOutcomes.Where(x => !x.Synced).Select(x => x.EmployeeNo)
+                        : selection.Employees
+                            .Where(x => string.Equals(
+                                x.DepartmentId,
+                                departmentId,
+                                StringComparison.OrdinalIgnoreCase))
+                            .Select(x => x.SerialNumber)));
+            if (!string.IsNullOrWhiteSpace(reason))
+                lines.Add("Reason : " + reason);
+
+            foreach (var failureGroup in departmentOutcomes
+                         .Where(x => !x.Synced)
+                         .GroupBy(x => DescribeInitialSyncFailure(x.Reason))
+                         .OrderBy(x => x.Key, StringComparer.OrdinalIgnoreCase))
+            {
+                lines.Add("Failure Reason : " + failureGroup.Key +
+                    " (" + failureGroup.Count() + " user(s))");
+            }
+
+            lines.Add("");
+        }
+
+        foreach (var departmentId in selection.InactiveDepartmentIds
+                     .OrderBy(x => x, StringComparer.OrdinalIgnoreCase))
+        {
+            lines.Add("Department " + departmentId + " : NOT SYNCED");
+            lines.Add("Eligible Users : 0");
+            lines.Add("Synced Users : 0");
+            lines.Add("Failed Users : 0");
+            lines.Add("Reason : Department is inactive.");
+            lines.Add("");
+        }
+
+        foreach (var departmentId in selection.MissingDepartmentIds
+                     .OrderBy(x => x, StringComparer.OrdinalIgnoreCase))
+        {
+            lines.Add("Department " + departmentId + " : NOT SYNCED");
+            lines.Add("Eligible Users : 0");
+            lines.Add("Synced Users : 0");
+            lines.Add("Failed Users : 0");
+            lines.Add("Reason : Department was not found.");
+            lines.Add("");
+        }
+
+        if (selection.ActiveDepartmentIds.Count == 0 &&
+            selection.InactiveDepartmentIds.Count == 0 &&
+            selection.MissingDepartmentIds.Count == 0)
+        {
+            lines.Add("No active departments were available for synchronization.");
+            lines.Add("");
+        }
+
+        var totalSynced = outcomes.Count(x => x.Synced);
+        lines.Add("TOTAL SYNCED USERS : " + totalSynced);
+        lines.Add("TOTAL FAILED USERS : " + Math.Max(0, selection.Employees.Count - totalSynced));
+        lines.Add("");
+
+        _logger.Biz(BizChannel.DepartmentalSync, lines.ToArray());
+        _logger.BizSeparator(BizChannel.DepartmentalSync);
+    }
+
+    private static void AppendSqlParameters(StringBuilder sql, string prefix, int count)
+    {
+        for (int i = 0; i < count; i++)
+        {
+            if (i > 0)
+                sql.Append(',');
+            sql.Append(prefix).Append(i);
+        }
+    }
+
+    private static void AddSqlParameters(
+        MySqlCommand command,
+        string prefix,
+        IReadOnlyList<string> values)
+    {
+        for (int i = 0; i < values.Count; i++)
+            command.Parameters.AddWithValue(prefix + i, values[i]);
+    }
+
+    private static bool IsDatabaseActive(object value)
+    {
+        if (value == null || value == DBNull.Value)
+            return false;
+
+        if (value is bool boolValue)
+            return boolValue;
+
+        return string.Equals(
+            Convert.ToString(value, System.Globalization.CultureInfo.InvariantCulture)?.Trim(),
+            "1",
+            StringComparison.Ordinal);
+    }
+
+    private static string FormatLogValues(IEnumerable<string> values)
+    {
+        var items = (values ?? Enumerable.Empty<string>())
+            .Where(x => !string.IsNullOrWhiteSpace(x))
+            .ToList();
+        return items.Count == 0 ? "(none)" : string.Join(",", items);
+    }
+
     private static bool TryDownloadEmployeePortalPhoto(string photoUrl, out byte[] bytes, out string error)
     {
         bytes = Array.Empty<byte>();
@@ -489,6 +829,26 @@ internal sealed partial class HikvisionAttendanceManager
     {
         public string Id { get; set; } = "";
         public string SerialNumber { get; set; } = "";
+        public string DepartmentId { get; set; } = "";
         public string Name { get; set; } = "";
     }
+
+    private sealed class InitialSyncEmployeeOutcome
+    {
+        public string DepartmentId { get; set; } = "";
+        public string EmployeeNo { get; set; } = "";
+        public bool Synced { get; set; }
+        public string Reason { get; set; } = "";
+    }
+
+    private sealed class InitialSyncSelection
+    {
+        public int LocationSiteId { get; set; }
+        public List<InitialSyncEmployee> Employees { get; } = new List<InitialSyncEmployee>();
+        public List<string> ActiveDepartmentIds { get; } = new List<string>();
+        public List<string> InactiveDepartmentIds { get; } = new List<string>();
+        public List<string> MissingDepartmentIds { get; } = new List<string>();
+        public int InactiveDepartmentCount { get; set; }
+        public int SkippedInactiveEmployeeCount { get; set; }
+    }
 }
diff --git a/HikvisionAttendanceWindowsService.cs b/HikvisionAttendanceWindowsService.cs
index 527e1ca..db039dc 100644
--- a/HikvisionAttendanceWindowsService.cs
+++ b/HikvisionAttendanceWindowsService.cs
@@ -120,6 +120,13 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
         [DataMember]
         public List<string> InitialSyncEmployeeIds { get; set; } = new List<string>();
 
+        /// <summary>
+        /// Required HRMS employee.location_site_id filter for Initial Department Sync.
+        /// Null or a non-positive value prevents the initial sync from running.
+        /// </summary>
+        [DataMember(EmitDefaultValue = false)]
+        public int? InitialSyncLocationSiteId { get; set; }
+
         /// <summary>When true, initial sync downloads JPEG photos from <see cref="EmployeePhotoBaseUrl"/>.</summary>
         [DataMember]
         public bool EnableEmployeePhotoSource { get; set; }
@@ -582,6 +589,8 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
                     cfg.InitialSyncDepartmentIds = new List<string>(overlay.InitialSyncDepartmentIds);
                 if (overlay.InitialSyncEmployeeIds != null)
                     cfg.InitialSyncEmployeeIds = new List<string>(overlay.InitialSyncEmployeeIds);
+                if (overlay.InitialSyncLocationSiteId.HasValue)
+                    cfg.InitialSyncLocationSiteId = overlay.InitialSyncLocationSiteId;
                 cfg.EnableEmployeePhotoSource = overlay.EnableEmployeePhotoSource;
                 if (overlay.EmployeePhotoBaseUrl != null)
                     cfg.EmployeePhotoBaseUrl = overlay.EmployeePhotoBaseUrl;
@@ -684,6 +693,9 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
         [DataMember]
         public List<string> InitialSyncEmployeeIds { get; set; } = new List<string>();
 
+        [DataMember(EmitDefaultValue = false)]
+        public int? InitialSyncLocationSiteId { get; set; }
+
         [DataMember]
         public bool EnableEmployeePhotoSource { get; set; }
 
@@ -773,6 +785,7 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
         private readonly string _attendanceBizDirectory;
         private readonly string _templateBizDirectory;
         private readonly string _userSyncBizDirectory;
+        private readonly string _departmentalSyncBizDirectory;
         private readonly string _unreachableBizDirectory;
         private readonly object _sync = new();
         public readonly BizSessionTotals Totals = new BizSessionTotals();
@@ -786,11 +799,13 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
             _attendanceBizDirectory = Path.Combine(logsRoot, "attendance_logs");
             _templateBizDirectory = Path.Combine(logsRoot, "template_fetching_logs");
             _userSyncBizDirectory = Path.Combine(logsRoot, "user_sync_logs");
+            _departmentalSyncBizDirectory = Path.Combine(logsRoot, "departmental_sync_logs");
             _unreachableBizDirectory = Path.Combine(_internalLogsDirectory, "unreachable_devices");
             Directory.CreateDirectory(_internalLogsDirectory);
             Directory.CreateDirectory(_attendanceBizDirectory);
             Directory.CreateDirectory(_templateBizDirectory);
             Directory.CreateDirectory(_userSyncBizDirectory);
+            Directory.CreateDirectory(_departmentalSyncBizDirectory);
             Directory.CreateDirectory(_unreachableBizDirectory);
         }
 
@@ -858,6 +873,7 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
             AppendBiz(BizChannel.Attendance, block);
             AppendBiz(BizChannel.UserSync, block);
             AppendBiz(BizChannel.Template, block);
+            AppendBiz(BizChannel.DepartmentalSync, block);
             AppendBiz(BizChannel.Unreachable, block);
         }
 
@@ -873,6 +889,7 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
             AppendBiz(BizChannel.Attendance, stopped);
             AppendBiz(BizChannel.UserSync, stopped);
             AppendBiz(BizChannel.Template, stopped);
+            AppendBiz(BizChannel.DepartmentalSync, stopped);
             AppendBiz(BizChannel.Unreachable, stopped);
         }
 
@@ -905,6 +922,9 @@ public sealed class HikvisionAttendanceWindowsService : ServiceBase
                 case BizChannel.Template:
                     path = Path.Combine(_templateBizDirectory, "template_fetching_logs_" + DateStamp() + ".txt");
                     break;
+                case BizChannel.DepartmentalSync:
+                    path = Path.Combine(_departmentalSyncBizDirectory, "departmental_sync_logs_" + DateStamp() + ".txt");
+                    break;
                 case BizChannel.Unreachable:
                     path = Path.Combine(_unreachableBizDirectory, "unreachable_devices_" + DateStamp() + ".txt");
                     break;