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Rate Limits

The IB Partner API applies rate limiting to protect service availability and prevent abuse.

Limits​

Limit typeDetails
Request rate100 requests per minute per API key
Failed lookupsRepeated failed lookups within a short window trigger a temporary 429 response

Handling 429 responses​

When you receive a 429 Too Many Requests, your integration should:

  1. Stop retrying immediately — sending more requests extends the lock-out window.
  2. Wait — pause for at least 60 seconds before trying again.
  3. Implement exponential back-off — on subsequent retries, double the wait time (60 s → 120 s → 240 s…).
  4. Check your logic — repeated 400 errors from invalid user_id values also count toward the failed-lookup limit.

Best practices​

  • Validate user_id client-side before calling the API. Only send UUIDs that you have reasonable confidence exist.
  • Cache successful results where your use-case allows — is_under_ib and date_joined rarely change in short windows.
  • Do not poll aggressively — this API is designed for on-demand checks, not continuous monitoring.