diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 52eb8b9..364731a 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -61,6 +61,19 @@ jobs:
             exit 1
           fi
 
+      # npm rejects a version that already exists, so a re-run of this
+      # workflow would fail on a release that published perfectly well.
+      - name: Skip if this version is already on npm
+        id: published
+        run: |
+          VERSION="$(node -p "require('./package.json').version")"
+          if npm view "newsdataapi@$VERSION" version >/dev/null 2>&1; then
+            echo "already=true" >> "$GITHUB_OUTPUT"
+            echo "::notice::newsdataapi@$VERSION is already on npm; skipping the publish (versions are immutable). Bump the version to publish again."
+          else
+            echo "already=false" >> "$GITHUB_OUTPUT"
+          fi
+
       # Tokenless OIDC trusted publishing — no NPM_TOKEN required. Provenance is
       # generated automatically. One-time setup on npmjs.com: open the package
       # → Settings → Trusted Publisher → add a GitHub Actions publisher with
@@ -69,4 +82,5 @@ jobs:
       #   Workflow filename:    publish.yml
       #   Environment:          npm   (optional; matches `environment:` above)
       - name: Publish to npm
+        if: steps.published.outputs.already != 'true'
         run: npm publish --provenance --access public
diff --git a/src/core/client.js b/src/core/client.js
index ddeaa05..f064000 100644
--- a/src/core/client.js
+++ b/src/core/client.js
@@ -5,6 +5,7 @@ import {
   ENDPOINTS,
   ENDPOINT_METHODS,
   RESULTS_OPTIONAL,
+  QUOTA_EXHAUSTED_CODES,
   WS_NEWS_TYPE,
   DEFAULT_REQUEST_TIMEOUT,
   DEFAULT_MAX_RETRIES,
@@ -30,6 +31,16 @@ export function redactApiKey(url) {
   return url.replace(/(apikey=)[^&]*/i, '$1REDACTED');
 }
 
+/**
+ * Whether a 429 body carries an error code meaning the account is out of API
+ * credits, as opposed to a transient rate limit.
+ */
+function isQuotaExhausted(body) {
+  const results = asObject(body)?.results;
+  const code = results && typeof results === 'object' ? results.code : undefined;
+  return typeof code === 'string' && QUOTA_EXHAUSTED_CODES.includes(code);
+}
+
 /** Parse a Retry-After header (integer seconds or HTTP-date) into ms. */
 function parseRetryAfter(value) {
   if (value === null || value === undefined) return null;
@@ -294,7 +305,9 @@ export class NewsDataApiClient {
 
       if (status === 429) {
         const retryAfter = parseRetryAfter(res.headers.get('retry-after'));
-        if (attempt >= this.#maxRetries) {
+        // A 429 covers a burst limit, a rate limit, and exhausted API
+        // credits. Only the first two are worth retrying.
+        if (isQuotaExhausted(body) || attempt >= this.#maxRetries) {
           throw new NewsdataRateLimitError(
             this.#errorMessage(body, status), 429, asObject(body),
             retryAfter === null ? null : Math.round(retryAfter / 1000),
diff --git a/src/core/constants.js b/src/core/constants.js
index e1b7de0..56799f3 100644
--- a/src/core/constants.js
+++ b/src/core/constants.js
@@ -56,6 +56,17 @@ export const WS_RECONNECT_DELAY = 1_000; // ms before the first reconnect; doubl
 export const WS_RECONNECT_DELAY_MAX = 30_000; // cap on the reconnect delay
 export const WS_OPEN_TIMEOUT = 10_000; // ms to wait for the opening handshake
 
+// Error codes on a 429 meaning the account's API credits are exhausted rather
+// than a transient rate limit. These are never retried — waiting out the
+// backoff cannot conjure more credits.
+//
+// `ApiLimitExceeded` is the documented code (see the ErrorCode enum in
+// https://newsdata.io/openapi.json); `ApiKeyLimitExceeded` is accepted too
+// because the API has been observed to send it and the spec is not exhaustive.
+export const QUOTA_EXHAUSTED_CODES = Object.freeze([
+  'ApiLimitExceeded', 'ApiKeyLimitExceeded',
+]);
+
 // Endpoints that require both from_date and to_date.
 export const REQUIRES_DATE_RANGE = Object.freeze(['count', 'crypto_count', 'market_count']);
 
diff --git a/test/client.test.js b/test/client.test.js
index 33fdebf..3111a29 100644
--- a/test/client.test.js
+++ b/test/client.test.js
@@ -129,3 +129,41 @@ test('redactApiKey hides the key', () => {
     'https://newsdata.io/api/1/latest?apikey=REDACTED&q=foo',
   );
 });
+
+// A 429 covers a burst limit, a rate limit, and exhausted API credits. Only
+// the first two are worth retrying.
+for (const code of ['ApiLimitExceeded', 'ApiKeyLimitExceeded']) {
+  test(`429 with ${code} is not retried`, async () => {
+    const body = { status: 'error', results: { message: 'limit', code } };
+    const fetchStub = stubFetch([
+      mockResponse(429, body), mockResponse(429, body), mockResponse(429, body),
+    ]);
+    const client = new NewsDataApiClient('key', {
+      fetch: fetchStub, retryBackoff: 1, retryBackoffMax: 1,
+    });
+
+    await assert.rejects(
+      () => client.latestApi({ q: 'x' }),
+      (err) => {
+        assert.ok(err instanceof NewsdataRateLimitError, `got ${err.name}`);
+        assert.deepEqual(err.responseBody, body);
+        return true;
+      },
+    );
+    assert.equal(fetchStub.calls.length, 1, 'exhausted quota must not retry');
+  });
+}
+
+test('429 without a quota code still retries', async () => {
+  const fetchStub = stubFetch([
+    mockResponse(429, { status: 'error', results: { message: 'slow', code: 'RateLimitExceeded' } }),
+    mockResponse(200, ok([{ title: 'recovered' }])),
+  ]);
+  const client = new NewsDataApiClient('key', {
+    fetch: fetchStub, retryBackoff: 1, retryBackoffMax: 1,
+  });
+
+  const res = await client.latestApi({ q: 'x' });
+  assert.equal(res.results[0].title, 'recovered');
+  assert.equal(fetchStub.calls.length, 2);
+});