diff --git a/src/components/DoWorkbench/WorkbenchEtraMergeDialog.tsx b/src/components/DoWorkbench/WorkbenchEtraMergeDialog.tsx
index d4bbc61..6f19978 100644
--- a/src/components/DoWorkbench/WorkbenchEtraMergeDialog.tsx
+++ b/src/components/DoWorkbench/WorkbenchEtraMergeDialog.tsx
@@ -25,6 +25,7 @@ import {
   mergeWorkbenchTickets,
   type WorkbenchMergeTicketCandidate,
 } from "@/app/api/doworkbench/actions";
+import { isWorkbenchMergeTicketNo } from "@/utils/workbenchReleaseType";
 
 const SWAL_ABOVE_DIALOG = {
   customClass: { container: "swal2-custom-zindex" },
@@ -306,15 +307,21 @@ const WorkbenchEtraMergeDialog: React.FC<Props> = ({
     const extra = filteredExtraTickets.find((x) => x.id === selectedExtraId);
     if (!batch || !extra) return;
 
+    const intoExistingTiM = isWorkbenchMergeTicketNo(batch.ticketNo);
+    const leftLabel = intoExistingTiM ? t("Merge ticket TI-M") : t("Batch/Single ticket");
+    const confirmHint = intoExistingTiM
+      ? t("Merge Etra ticket confirm hint into TI-M")
+      : t("Merge Etra ticket confirm hint");
+
     const confirm = await Swal.fire({
       ...SWAL_ABOVE_DIALOG,
       icon: "question",
       title: t("Merge Etra ticket confirm title"),
       html: `
         <div style="text-align:left;font-size:0.95em;">
-          <p><b>${t("Batch/Single ticket")}:</b> ${batch.ticketNo ?? batch.id}</p>
+          <p><b>${leftLabel}:</b> ${batch.ticketNo ?? batch.id}</p>
           <p><b>${t("Etra ticket")}:</b> ${extra.ticketNo ?? extra.id}</p>
-          <p style="margin-top:0.75em;color:#666;">${t("Merge Etra ticket confirm hint")}</p>
+          <p style="margin-top:0.75em;color:#666;">${confirmHint}</p>
         </div>
       `,
       showCancelButton: true,
@@ -406,7 +413,7 @@ const WorkbenchEtraMergeDialog: React.FC<Props> = ({
           ) : (
             <Stack direction={{ xs: "column", md: "row" }} spacing={2}>
               <MergeTicketCarousel
-                title={t("Batch/Single ticket")}
+                title={t("Merge left column title")}
                 items={batchTickets}
                 selectedId={selectedBatchId}
                 onSelect={(id) => {
diff --git a/src/i18n/en/pickOrder.json b/src/i18n/en/pickOrder.json
index e02ab80..3c76110 100644
--- a/src/i18n/en/pickOrder.json
+++ b/src/i18n/en/pickOrder.json
@@ -155,7 +155,9 @@
   "Etra Ticket Notice": "Etra Ticket Notice",
   "Merge Etra ticket": "Merge Etra ticket",
   "Merge Etra ticket dialog title": "Merge Etra into batch ticket",
-  "Merge Etra ticket lane hint": "Only unassigned tickets on the same shop, floor (2/F, 4/F, or Truck X), truck lane, and departure time can be merged. A new TI-M ticket will be created.",
+  "Merge Etra ticket lane hint": "Only unassigned tickets on the same shop, floor (2/F, 4/F, or Truck X), truck lane, and departure time can be merged. Left: batch/single or TI-M merge ticket.",
+  "Merge left column title": "Batch / Single / Merge ticket",
+  "Merge ticket TI-M": "TI-M merge ticket",
   "Batch/Single ticket": "Batch / Single ticket",
   "Etra ticket": "Etra ticket",
   "No mergeable batch tickets": "No unassigned batch or single tickets",
@@ -165,6 +167,7 @@
   "Merge Etra ticket confirm": "Confirm merge",
   "Merge Etra ticket confirm title": "Confirm merge batch and Etra tickets?",
   "Merge Etra ticket confirm hint": "A new TI-M ticket will be created; the original batch and Etra tickets will be archived.",
+  "Merge Etra ticket confirm hint into TI-M": "The Etra ticket will be folded into the selected TI-M; the Etra ticket will be archived.",
   "Merge Etra ticket success": "Merge completed",
   "Merge Etra ticket failed": "Merge failed",
   "Shop search": "Shop search",
diff --git a/src/i18n/zh/pickOrder.json b/src/i18n/zh/pickOrder.json
index dcf9b7c..ca353ab 100644
--- a/src/i18n/zh/pickOrder.json
+++ b/src/i18n/zh/pickOrder.json
@@ -157,7 +157,9 @@
   "Etra Ticket Notice": "目前是加單票，顯示與操作已切換為加單模式。",
   "Merge Etra ticket": "合併加單送貨訂單",
   "Merge Etra ticket dialog title": "合併加單送貨訂單和批次送貨訂單",
-  "Merge Etra ticket lane hint": "僅可合併同一店鋪、同一樓層（2/F、4/F 或車線-X）、同一車線與發車時間的未指派送貨訂單。",
+  "Merge Etra ticket lane hint": "僅可合併同一店鋪、同一樓層（2/F、4/F 或車線-X）、同一車線與發車時間的未指派送貨訂單。左側可選批次／單張票或 TI-M 合併票。",
+  "Merge left column title": "批次／單張／合併票",
+  "Merge ticket TI-M": "TI-M 合併票",
   "Batch/Single ticket": "批次／單張 送貨訂單",
   "Etra ticket": "加單送貨訂單",
   "No mergeable batch tickets": "暫無可合併的批次／單張 送貨訂單",
@@ -167,6 +169,7 @@
   "Merge Etra ticket confirm": "確認合併",
   "Merge Etra ticket confirm title": "確認合併批次／加單送貨訂單？",
   "Merge Etra ticket confirm hint": "將產生新 TI-M 合併票，原批次票與加單票將歸檔。",
+  "Merge Etra ticket confirm hint into TI-M": "加單票將併入所選 TI-M，原加單票將歸檔。",
   "Merge Etra ticket success": "合併成功",
   "Merge Etra ticket failed": "合併失敗",
   "Next": "下一頁",
@@ -178,6 +181,8 @@
   "batch": "批量",
   "single": "單張",
   "isExtra": "加單",
+  "isExtrabatch": "合併批量",
+  "isExtrasingle": "合併單張",
   "Pick Order": "提料單",
   "Type": "類型",
   "Product Type": "貨品類型",
diff --git a/src/utils/workbenchReleaseType.ts b/src/utils/workbenchReleaseType.ts
index 1c02374..9425f3d 100644
--- a/src/utils/workbenchReleaseType.ts
+++ b/src/utils/workbenchReleaseType.ts
@@ -1,3 +1,7 @@
+export function isWorkbenchMergeTicketNo(ticketNo?: string | null): boolean {
+  return (ticketNo ?? "").trim().toUpperCase().startsWith("TI-M-");
+}
+
 /** Workbench ticket carries extra DOs when releaseType or legacy TI-E- ticket. */
 export function isWorkbenchExtraTicket(
   releaseType?: string | null,