diff --git a/src/lib/server/stock-quantities-bulk-service.test.ts b/src/lib/server/stock-quantities-bulk-service.test.ts
index 9cac01f..c640e1c 100644
--- a/src/lib/server/stock-quantities-bulk-service.test.ts
+++ b/src/lib/server/stock-quantities-bulk-service.test.ts
@@ -21,6 +21,16 @@ const STOCK_ITEMS = [
     current_qty: 5,
     is_active: true,
   },
+  // A second item with the same wording, so a text-only line has two
+  // equally good candidates and comes back ambiguous.
+  {
+    id: "id-amb",
+    sku: "BOLT-M6-40-ALT",
+    name: "Bolt M6 40mm",
+    description: "Hex bolt M6 x 40mm",
+    current_qty: 7,
+    is_active: true,
+  },
 ];
 
 function stubPb(
@@ -212,10 +222,17 @@ describe("setStockQuantitiesBulk — applying", () => {
     expect(res.summary.applied).toBe(1);
     expect(res.results[0].status).toBe("applied");
     expect(res.results[0].new_qty).toBe(50);
-    // The failed row is reported on its own, with the reason.
-    expect(res.summary.unmatched).toBe(1);
-    expect(res.results[1].status).toBe("unmatched");
+    // The failed row is reported on its own, with the reason. It is
+    // NOT "unmatched" — the SKU was fine, the write was not.
+    expect(res.summary.failed).toBe(1);
+    expect(res.summary.unmatched).toBe(0);
+    expect(res.results[1].status).toBe("failed");
     expect(res.results[1].message).toContain("Failed to update");
+    // Every line is counted once, in exactly one bucket.
+    const { applied, unchanged, unmatched, ambiguous, failed } = res.summary;
+    expect(res.summary.total).toBe(
+      applied + unchanged + unmatched + ambiguous + failed,
+    );
   });
 
   it("applies the good lines and reports the unmatched one", async () => {
@@ -237,6 +254,45 @@ describe("setStockQuantitiesBulk — applying", () => {
   });
 });
 
+describe("setStockQuantitiesBulk — summary", () => {
+  it("counts every line once, in exactly one bucket", async () => {
+    const { pb } = stubPb([], { failUpdateIds: ["id-def"] });
+    const res = await setStockQuantitiesBulk({
+      pb,
+      lines: [
+        { sku: "M16-FLAT-WASHER", qty: 50 }, // applied
+        { sku: "BOLT-M6-40-ALT", qty: 7 }, // unchanged — it holds 7
+        { sku: "ZZZ-9", qty: 30 }, // unmatched
+        { description: "Bolt M6 40mm", qty: 5 }, // ambiguous — two items
+        { sku: "BOLT-M6-40", qty: 9 }, // failed — the write blows up
+      ],
+      mode: "set",
+      dryRun: false,
+      actor: { id: "u1", name: "Dave" },
+    });
+
+    expect(res.summary).toEqual({
+      total: 5,
+      applied: 1,
+      unchanged: 1,
+      unmatched: 1,
+      ambiguous: 1,
+      failed: 1,
+    });
+    expect(res.results.map((r) => r.status)).toEqual([
+      "applied",
+      "unchanged",
+      "unmatched",
+      "ambiguous",
+      "failed",
+    ]);
+    const { applied, unchanged, unmatched, ambiguous, failed } = res.summary;
+    expect(res.summary.total).toBe(
+      applied + unchanged + unmatched + ambiguous + failed,
+    );
+  });
+});
+
 describe("setStockQuantitiesBulk — price_list mirror", () => {
   it("mirrors the new quantity onto every catalogue row for that SKU", async () => {
     const { pb, priceListUpdates } = stubPb([
diff --git a/src/lib/server/stock-quantities-bulk-service.ts b/src/lib/server/stock-quantities-bulk-service.ts
index 9554741..51186c2 100644
--- a/src/lib/server/stock-quantities-bulk-service.ts
+++ b/src/lib/server/stock-quantities-bulk-service.ts
@@ -73,11 +73,27 @@ export type StockQuantitiesBulkInput = {
   actor: { id: string; name: string };
 };
 
+/**
+ * What happened to one pasted line.
+ *
+ *   - "applied"   — the quantity was written (or, on a dry run, would be).
+ *   - "unchanged" — the item already held that quantity; nothing written.
+ *   - "unmatched" — the line never resolved to an active stock item:
+ *                   nothing matched the SKU or the text, or the best
+ *                   match was an inactive item.
+ *   - "ambiguous" — several items matched equally well; a person picks.
+ *   - "failed"    — the line matched, but the write did not complete.
+ *
+ * "unmatched" and "failed" are deliberately apart: the first means
+ * "check the SKU or activate the item", the second means "the write
+ * blew up — retry it". The reason for each is in the row's message.
+ */
 export type StockQuantitiesBulkRowStatus =
   | "applied"
   | "unchanged"
   | "unmatched"
-  | "ambiguous";
+  | "ambiguous"
+  | "failed";
 
 export type StockQuantitiesBulkResultRow = {
   /** The SKU as the operator typed it. */
@@ -113,6 +129,8 @@ export type StockQuantitiesBulkResult = {
     unchanged: number;
     unmatched: number;
     ambiguous: number;
+    /** The line matched, but the write did not complete. */
+    failed: number;
   };
   results: StockQuantitiesBulkResultRow[];
 };
@@ -175,6 +193,8 @@ async function mirrorPriceListQty(
   const norm = normaliseSku(rawSku);
   if (!norm) return 0;
 
+  // One page is enough at the catalogue's size: a SKU has one
+  // row per supplier, so a handful at most.
   const page = await pb
     .collection("price_list")
     .getList<PriceListRow>(1, 200, {
@@ -284,12 +304,15 @@ export async function setStockQuantitiesBulk(
   }
 
   const results: StockQuantitiesBulkResultRow[] = [];
+  // One line lands in exactly one of these counts, so they add up
+  // to `total`.
   const summary = {
     total: lines.length,
     applied: 0,
     unchanged: 0,
     unmatched: 0,
     ambiguous: 0,
+    failed: 0,
   };
 
   for (let i = 0; i < planned.length; i++) {
@@ -312,6 +335,9 @@ export async function setStockQuantitiesBulk(
       continue;
     }
 
+    // The line never resolved to an active stock item — nothing
+    // matched, or the best match was inactive. The resolver's
+    // message says which.
     if (line.status === "unmatched" || !line.item || p.target === undefined) {
       summary.unmatched += 1;
       results.push({ ...base, status: "unmatched", message: line.message });
@@ -356,11 +382,14 @@ export async function setStockQuantitiesBulk(
 
     const writeRow = writeByPlanIndex.get(i);
 
+    // The line resolved, but the write did not complete. That is
+    // its own outcome: the operator should retry, not go hunting
+    // for a typo in the SKU.
     if (!writeRow || writeRow.ok === false) {
-      summary.unmatched += 1;
+      summary.failed += 1;
       results.push({
         ...base,
-        status: "unmatched",
+        status: "failed",
         match_method: line.match_method,
         id: line.item.id,
         name: line.item.name,