API documentation

API Rate Limits

The current public request-rate rule and how to stay within it.

Current public limit

6 API calls per 10 seconds per IP address. This is a request-rate rule, not a monthly allowance.

If you receive HTTP 429

Stop the burst and wait before trying again. Follow Retry-After when the response provides it. Repeated immediate retries can make the problem worse.

Good client behaviour

  • Cache successful postal lookups when your freshness needs allow it.
  • Debounce type-ahead search instead of sending a request for every key press.
  • Cancel search requests that are no longer needed.
  • Avoid repeating the same lookup many times in a short period.
  • Use bounded retries only for temporary failures.

Fair use

Do not rotate IP addresses, proxies or accounts to avoid the rate limit. See the Abuse Policy for fair-use rules.