To maintain system reliability and provide a fair experience across users, Antei enforces strict rate limits across its API. These limits vary slightly between the Live and Sandbox environments.

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Live Environment Limits

API GroupRate Limit
/v1/tax/rate, /v1/tax/id-validate, /v1/tax/unify1000 requests per minute
Other endpoints (e.g., /customers, /invoices, etc.)300 requests per minute

These limits apply per API key, Org, User, IP Address, across all paid plans.

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Sandbox Environment Limits

API GroupRate Limit
/v1/tax/rate, /v1/tax/id-validate, /v1/tax/unify30 requests per minute
Other endpoints (e.g., /customers, /invoices)Not available in sandbox

Sandbox is intended for testing and development. It enforces tighter limits to simulate real-world constraints and prevent abuse.

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Response Headers

Each API response returns rate limit headers so you can monitor usage:

HeaderDescription
X-RateLimit-LimitMax allowed requests per minute
X-RateLimit-RemainingRemaining calls in the current window
X-RateLimit-ResetTime (Unix epoch) when the rate limit resets
Response
{ "X-RateLimit-Limit": 1000,
"X-RateLimit-Remaining": 846,
"X-RateLimit-Reset": 1717061820 }

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Exceeding Limits

When you exceed the limit:

  • You’ll receive a 429 Too Many Requests error
  • The response will include a helpful message
  • Headers will guide retry timing

Retry-After headers may be included to indicate how long to wait before retrying.

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Best Practices

Cache tax results wherever possible
Use exponential backoff on 429 errors
Monitor rate limit headers programmatically

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Need More?

For higher throughput or enterprise needs, contact support@antei.com with your expected volume and use case.