diff --git a/scripts/book-invoice.mjs b/scripts/book-invoice.mjs
index ab1ad94..7fe75d4 100644
--- a/scripts/book-invoice.mjs
+++ b/scripts/book-invoice.mjs
@@ -74,6 +74,40 @@ if (!targets.length) {
 const allLines = await pb.collection("invoice_lines").getFullList({ sort: "line_no" });
 const existingIncome = await pb.collection("monthly_income").getFullList();
 
+// ---- Repair stale booking pointers ------------------------------------------------
+// `booked_asset` stores an asset RECORD ID, and `npm run seed` deletes and re-creates
+// every asset — so the id a line was booked against stops existing after a seed. The line
+// then points at nothing and silently drops out of monthly_income, which is exactly the
+// "it booked yesterday and is unbooked today" symptom.
+//
+// The invoice line already carries the register code it was matched on (`asset_code`),
+// so the pointer can be re-derived rather than retyped. This ONLY ever points a line at
+// the asset its own code names; it never invents a match and never clears one, so a line
+// with no code stays unbooked exactly as before.
+const allAssets = await pb.collection("assets").getFullList();
+const assetIds = new Set(allAssets.map((a) => a.id));
+const idByCode = new Map(allAssets.filter((a) => a.code).map((a) => [String(a.code).trim().toUpperCase(), a.id]));
+const codeFromMachine = (code) => {
+  const m = /^([A-Za-z]+)[- ]?([0-9]{1,3})/.exec(String(code || "").trim());
+  return m ? `${m[1].toUpperCase()}${m[2]}` : "";
+};
+
+let repaired = 0;
+if (!dryRun) {
+  for (const l of allLines) {
+    if (l.booked_site) continue; // booked to a site — a different, deliberate choice
+    const fresh = (String(l.asset_code || "").trim().toUpperCase() || codeFromMachine(l.machine_code))
+      && idByCode.get(String(l.asset_code || "").trim().toUpperCase() || codeFromMachine(l.machine_code));
+    // Only act when the pointer is genuinely gone: empty, or pointing at a deleted asset.
+    const needsRepair = !l.booked_asset || !assetIds.has(l.booked_asset);
+    if (!needsRepair || !fresh || fresh === l.booked_asset) continue;
+    await pb.collection("invoice_lines").update(l.id, { booked_asset: fresh });
+    l.booked_asset = fresh;
+    repaired++;
+  }
+}
+if (repaired) console.log(`  · re-linked ${repaired} line(s) whose target asset had been replaced by a seed`);
+
 // Remove previously invoice-derived rows for the target invoices only.
 const targetIds = new Set(targets.map((i) => i.id));
 const linesOfTargets = allLines.filter((l) => targetIds.has(l.invoice));