diff --git a/package.json b/package.json
index 5d5a1ec..a510a8e 100644
--- a/package.json
+++ b/package.json
@@ -29,8 +29,9 @@
     "pb:migrate:price-list-sku-normalised": "npx tsx scripts/migrations/2026-06-30-add-price-list-sku-normalised.ts",
     "pb:migrate:quote-items-sku": "npx tsx scripts/migrations/2026-06-30-add-quote-items-sku-and-pricing.ts",
     "pb:migrate:rfq-outbound": "npx tsx scripts/migrations/2026-06-30-create-rfq-outbound.ts",
-    "pb:migrate:sprint-categories": "npx tsx scripts/migrations/2026-07-02-add-sprint-categories-and-claims.ts",
+    "pb:migrate:sprint-categories": "npx tsx scripts/migrations/2026-07-02-add-sprint-categories-and-claims.ts",
     "pb:migrate:po-pdf-tokens": "npx tsx scripts/migrations/2026-07-09-po-pdf-tokens.ts",
+    "pb:migrate:po-additional-attachments": "npx tsx scripts/migrations/2026-07-09-po-additional-attachments.ts",
     "smoke:counter": "npx tsx scripts/smoke/counter.ts",
     "smoke:counter-concurrent": "npx tsx scripts/smoke/counter-concurrent.ts",
     "smoke:create-from-email": "npx tsx scripts/smoke/create-from-email.ts",
diff --git a/scripts/migrations/2026-07-09-po-additional-attachments.ts b/scripts/migrations/2026-07-09-po-additional-attachments.ts
new file mode 100644
index 0000000..862576e
--- /dev/null
+++ b/scripts/migrations/2026-07-09-po-additional-attachments.ts
@@ -0,0 +1,55 @@
+// scripts/migrations/2026-07-09-po-additional-attachments.ts
+//
+// One-shot schema migration: add an `additional_attachments` file
+// field to the `purchase_orders` collection. Same shape as
+// `documents` (file, multi, no PB cap, any mime type).
+//
+// Why this exists: the operator wants to attach supporting files
+// (supplier quotes, drawings, NDAs) to a PO that travel with the
+// outbound email alongside the versioned PDF. We use a separate
+// field rather than stuffing extras into `documents` so the
+// `documents ↔ documents_history` invariant the PDF download
+// path depends on stays clean.
+//
+// Idempotent: re-running is a no-op when the field is already present.
+
+import { getAdminPocketBase } from "@/lib/server/pocketbase-admin";
+
+const COLLECTION_NAME = "purchase_orders";
+const FIELD_NAME = "additional_attachments";
+
+async function main() {
+  const pb = await getAdminPocketBase();
+
+  const collection = await pb.collections.getOne(COLLECTION_NAME);
+  const existing = (collection.fields ?? []) as Array<{ name: string }>;
+  if (existing.some((f) => f.name === FIELD_NAME)) {
+    console.log(`[po-additional-attachments] field already present on ${COLLECTION_NAME}`);
+    return;
+  }
+
+  const newField = {
+    name: FIELD_NAME,
+    type: "file",
+    required: false,
+    presentable: false,
+    protected: false,
+    maxSelect: 0,
+    maxSize: 0,
+    mimeTypes: null,
+    thumbs: null,
+  };
+
+  await pb.collections.update(collection.id, {
+    fields: [...existing, newField],
+  });
+
+  console.log(
+    `[po-additional-attachments] created field on ${COLLECTION_NAME} (file, multi, any mime)`,
+  );
+}
+
+main().catch((err) => {
+  console.error("[po-additional-attachments] failed:", err);
+  process.exit(1);
+});
\ No newline at end of file