# Rating Limiting When using the SQR B2B API, all clients are subject to rate limits. Rate limiting ensures fair use, protects the platform from abuse, and maintains a high level of performance and availability for all customers. Understanding these limits is important to avoid request throttling and to design integrations that handle rate-limited responses gracefully. Rate limiting is applied based on your assigned service credentials. ## Walkthrough If a client exceeds the configured request rate, burst capacity, or quota, the API will respond with an `HTTP 429` `Too Many Requests` error. At this point, the client must delay further requests until the rate limit window resets. ## Best Practices * Implement retry logic – Handle `HTTP 429` `Too Many Requests` responses using exponential backoff before retrying. * Distribute requests – Spread requests evenly instead of sending large bursts. * Cache results – Cache frequently used API responses to minimize repeated calls.