ERR_API_LIMIT on Zapier: API call limit reached. Root cause: Your account has exhausted its monthly or daily API call quota for this platform. Each API request — including background syncs, webhook deliveries, and scheduled automations — counts against this limit. High-frequency automations or bulk operations can deplete quotas faster than expected. Step 1: Identify which app is enforcing the API limit. The error message will usually name the app whose API limit was hit — for example, "Google Sheets API limit exceeded" or "HubSpot API rate limit reached". This is the app's limit, not Zapier's task limit. Go to zapier.com/app/history, find the failed task, and click it to expand the error details. The full error message will include the HTTP status code (usually 429 Too Many Requests) and often a Retry-After header value telling you how long to wait. Note the app name and the limit type (per-minute, per-day, or per-month) before proceeding. Step 2: Check your current API usage in the connected app's dashboard. Log into the connected app directly and navigate to its API or developer settings. In Google Cloud Console, go to APIs & Services → Dashboard → select the API → check Quotas. In HubSpot, go to Settings → Integrations → API Key → Usage. In Salesforce, go to Setup → System Overview → API Usage. These dashboards show your actual consumption against your plan's limit, which tells you whether you are consistently near the limit (a structural problem) or hit it due to a one-off spike. Step 3: Add a Delay step to spread API calls over time. If your Zap processes many records in a short burst, add a Zapier Delay step between the trigger and the action. Go to the Zap editor → click the + between steps → search for "Delay" → add "Delay For" with a value of 1–5 seconds. This slows the Zap's processing rate and prevents it from hitting per-minute API limits. For bulk operations that process hundreds of records, a 2-second delay reduces throughput to ~30 records per minute, which stays within most apps' standard rate limits. Step 4: Consolidate multiple Zaps that call the same API into a single Zap. If you have several Zaps all calling the same app's API, their combined call volume may exceed the limit even though each individual Zap looks reasonable. Go to zapier.com/app/zaps and filter by the connected app. Count how many Zaps use it as an action. Consider merging related Zaps using Zapier's Paths feature (available on Professional plan and above) — one trigger can branch into multiple paths, reducing the number of separate Zaps hitting the same API. Step 5: Enable Zapier's automatic retry for rate-limited tasks. Zapier automatically retries tasks that fail with a 429 status code, but only if the Zap is configured correctly. In the Zap editor, click the action step → click "Error handling" → enable "Retry on error". Zapier will retry the failed task up to 3 times with exponential backoff (waiting 1 minute, then 5 minutes, then 25 minutes). This handles temporary rate limit spikes without requiring manual intervention. Check zapier.com/app/history the next day to confirm retried tasks succeeded. Step 6: Upgrade the connected app's plan if you are consistently near the limit. If your API usage dashboard shows you regularly consuming 80–100% of your quota, an upgrade is more reliable than optimisation alone. Before upgrading, export your usage data for the past 30 days and calculate your average daily consumption. Multiply by 1.5 to get a comfortable headroom target, then find the plan that provides that quota. For Google Workspace APIs, request a quota increase at console.cloud.google.com/iam-admin/quotas — Google often grants increases for free if you provide a business justification.