diff --git a/README.md b/README.md
index 203dfba..f44f717 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Car, motorcycle and truck make and model dropdown
 
-**The make/model picker you stopped hand-maintaining.** `make-model-dropdown` turns two `<select>` elements into a dependent make → model dropdown, populated live from the [VehiclesDB API](https://vehiclesdb.com/api): **14,000+ models across 850+ makes**, six vehicle kinds — cars, motorcycles (motorbikes), mopeds, vans, trucks and buses — reconciled from the official vehicle registers of 14 countries and refreshed monthly. One `kind` option turns the same widget into a car picker, a motorcycle picker or a truck picker.
+**The make/model picker you stopped hand-maintaining.** `make-model-dropdown` turns two `<select>` elements into a dependent make → model dropdown, populated live from the [VehiclesDB API](https://vehiclesdb.com/api): **14,000+ models across 850+ makes**, six vehicle kinds — cars, motorcycles (motorbikes), mopeds, vans, trucks and buses — reconciled from the official vehicle registers of 15 countries and refreshed monthly. One `kind` option turns the same widget into a car picker, a motorcycle picker or a truck picker.
 
 Zero dependencies. No build step. Works with plain HTML forms, React, Vue, Rails, anything that renders a `<select>`.
 
diff --git a/make-model-dropdown.js b/make-model-dropdown.js
index 61cc8f8..2ca1fd2 100644
--- a/make-model-dropdown.js
+++ b/make-model-dropdown.js
@@ -4,7 +4,7 @@
  *
  * A dependent make → model picker for any web page, powered by the VehiclesDB
  * API: 14,000+ models across 850+ makes (cars, motorcycles, mopeds, vans,
- * trucks, buses), reconciled from official registers of 14 countries.
+ * trucks, buses), reconciled from official registers of 15 countries.
  *
  * Zero dependencies. No build step. MIT licensed.
  * Data: CC-BY 4.0 (identity layer) — the widget renders attribution for you.
diff --git a/package.json b/package.json
index c0245df..4d9a616 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "make-model-dropdown",
-  "version": "0.1.4",
-  "description": "Car make and model dropdown for any web page. A dependent make/model picker with live vehicle data from the VehiclesDB API: 14,000+ models, 850+ makes, cars and motorcycles to trucks and buses, from official registers of 14 countries. Zero dependencies.",
+  "version": "0.1.5",
+  "description": "Car make and model dropdown for any web page. A dependent make/model picker with live vehicle data from the VehiclesDB API: 14,000+ models, 850+ makes, cars and motorcycles to trucks and buses, from official registers of 15 countries. Zero dependencies.",
   "keywords": [
     "car make model dropdown",
     "motorcycle make model dropdown",
@@ -25,7 +25,9 @@
   "bugs": "https://github.com/vehiclesdb/make-model-dropdown/issues",
   "license": "MIT",
   "scripts": {
-    "test": "node --test"
+    "test": "node --test",
+    "sync:countries": "node scripts/sync-countries.mjs",
+    "prepublishOnly": "node scripts/sync-countries.mjs --check"
   },
   "main": "make-model-dropdown.js",
   "exports": {
diff --git a/scripts/sync-countries.mjs b/scripts/sync-countries.mjs
new file mode 100644
index 0000000..8fc6d4f
--- /dev/null
+++ b/scripts/sync-countries.mjs
@@ -0,0 +1,66 @@
+#!/usr/bin/env node
+// sync-countries.mjs — keep "official registers of N countries" true.
+//
+// The country count in package.json's npm description, the library header and
+// the README is a FACT about the VehiclesDB dataset, so it is read from the
+// dataset's own manifest.json (`countries`, the register countries of the
+// release) instead of being typed by hand. It said "14" for two releases after
+// the dataset reached 15 (found 2026-10-10).
+//
+//   node scripts/sync-countries.mjs                    # rewrite from the published manifest
+//   node scripts/sync-countries.mjs --manifest path    # or a local/other manifest (path or URL)
+//   node scripts/sync-countries.mjs --check            # exit 1 if any file is stale (prepublishOnly)
+//
+// Zero dependencies (Node >= 18 global fetch).
+import { readFileSync, writeFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import path from "node:path";
+
+export const DEFAULT_MANIFEST = "https://raw.githubusercontent.com/vehiclesdb/vehiclesdb/main/manifest.json";
+export const FILES = ["package.json", "make-model-dropdown.js", "README.md"];
+const PHRASE = /(registers of )(\d+)( countries)/g;
+
+export function countryCount(manifest) {
+  const list = manifest && manifest.countries;
+  if (!Array.isArray(list) || list.length === 0) throw new Error("manifest has no `countries` array");
+  return new Set(list.map((c) => String(c).toLowerCase())).size;
+}
+
+export function rewrite(text, n) {
+  return text.replace(PHRASE, (_m, a, _old, b) => `${a}${n}${b}`);
+}
+
+async function loadManifest(src) {
+  if (/^https?:\/\//.test(src)) {
+    const res = await fetch(src);
+    if (!res.ok) throw new Error(`manifest fetch ${res.status}: ${src}`);
+    return res.json();
+  }
+  return JSON.parse(readFileSync(src, "utf8"));
+}
+
+async function main(argv) {
+  const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
+  const i = argv.indexOf("--manifest");
+  const src = i >= 0 ? argv[i + 1] : DEFAULT_MANIFEST;
+  const check = argv.includes("--check");
+  const n = countryCount(await loadManifest(src));
+  const stale = [];
+  for (const f of FILES) {
+    const p = path.join(root, f);
+    const before = readFileSync(p, "utf8");
+    const after = rewrite(before, n);
+    if (after === before) continue;
+    stale.push(f);
+    if (!check) writeFileSync(p, after);
+  }
+  if (check && stale.length) {
+    console.error(`stale country count (manifest says ${n}): ${stale.join(", ")} — run: node scripts/sync-countries.mjs`);
+    process.exit(1);
+  }
+  console.log(`${check ? "checked" : "synced"}: ${n} countries (${src})${stale.length && !check ? `; updated ${stale.join(", ")}` : ""}`);
+}
+
+if (process.argv[1] && fileURLToPath(import.meta.url) === path.resolve(process.argv[1])) {
+  main(process.argv.slice(2)).catch((e) => { console.error(e.message); process.exit(1); });
+}
diff --git a/test/sync-countries.test.mjs b/test/sync-countries.test.mjs
new file mode 100644
index 0000000..253a4ae
--- /dev/null
+++ b/test/sync-countries.test.mjs
@@ -0,0 +1,14 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { countryCount, rewrite } from "../scripts/sync-countries.mjs";
+
+test("counts distinct register countries from the manifest", () => {
+  assert.equal(countryCount({ countries: ["ar", "ca", "de", "GB", "gb"] }), 4);
+  assert.throws(() => countryCount({}), /no `countries`/);
+});
+
+test("rewrites every 'registers of N countries' phrase and nothing else", () => {
+  const src = "from official registers of 14 countries. 14,000+ models; registers of 14 countries";
+  assert.equal(rewrite(src, 15), "from official registers of 15 countries. 14,000+ models; registers of 15 countries");
+  assert.equal(rewrite("no phrase here", 15), "no phrase here");
+});