What is API Rate Limiting?
API Rate Limiting is Restrictions on how many API calls you can make to a service within a given time period.
Definition
API rate limiting controls how fast you can request data from a service. Most B2B data tools impose limits: Salesforce allows 100,000 API calls per 24 hours on Enterprise, HubSpot gives 500,000/day on Professional, and enrichment APIs like Clearbit cap at 600 requests/minute. Exceeding limits returns 429 (Too Many Requests) errors and can temporarily block your access. Rate limits exist to protect service stability, but they create real constraints when you're running bulk operations like mass enrichment or large CRM syncs.
Why It Matters
Rate limits determine what's operationally possible. If your enrichment provider limits you to 100 calls/minute, enriching 50,000 records takes over 8 hours. If your CRM limits daily API calls and you have three integrations competing for that budget, something breaks. Understanding rate limits before you buy prevents discovering your workflow is impossible after you've signed an annual contract.
Example
A RevOps team builds a real-time enrichment flow: form submission triggers Zapier, which calls Clearbit, then writes to Salesforce. During a webinar with 2,000 registrations in 30 minutes, they hit Clearbit's rate limit at 600/min. The remaining 1,400 records queue up and enrich over the next 90 minutes instead of instantly. They switch to batch processing for high-volume events.
Tools for API Rate Limiting
Find the Right API Rate Limiting Tool
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