Zoho CRM API limits and credits: why your integration or sync keeps failing

API credits: a rolling 24-hour allowance

Zoho's v8 API limits page says each API call reduces your credits, with most calls costing 1 credit, and that the limit works on "a rolling 24-hour window, from the start of the call". Your allowance is based on your edition, your number of user licences and any add-on credits.

Zoho's page gives a base of 50,000 credits for paid editions, plus a per-user amount that rises with the edition (250 per user on Standard/Starter, 500 on Professional, 1,000 on Enterprise/Zoho One, 2,000 on Ultimate/CRM Plus), with maximums that also vary by edition. The Free edition is given 5,000 credits. Older Zoho pages and community posts quote different bases and maximums, so confirm against your own account rather than a blog post, including this one.

Source: Zoho CRM API v8: API limits

What different calls cost

Not every call costs one credit. Per Zoho's page:

• Insert, update and upsert calls cost 1 credit for every 10 records.
• COQL queries cost 1 credit for a LIMIT of 1 to 200, 2 credits for 201 to 1,000, and 3 credits for 1,001 to 2,000.
• A composite request costs 1 credit.
• Bulk read initialisation costs 50 credits and bulk write initialisation 500.
• Convert Lead costs 5, Send Mail 20, Merge Records 50 and Mass Convert Leads 200.
• All other APIs cost 1 credit.

Source: Zoho CRM API v8: API limits

Concurrency: calls running at the same time

Separate from daily credits, Zoho limits how many calls can be active simultaneously per organisation per app: 5 on Free, 10 on Standard/Starter, 15 on Professional, 20 on Enterprise/Zoho One and 25 on Ultimate/CRM Plus. Zoho also describes a sub-concurrency limit of 10 for all editions, which applies to insert, update and upsert calls with more than 10 records, and to the Composite API. When it is exceeded, Zoho says the system throws a TOO_MANY_REQUESTS error.

This is why a sync can fail even when the daily total looks fine: a burst of parallel jobs can breach concurrency while credits remain.

Source: Zoho CRM API v8: API limits

Custom function limits

Custom functions (Deluge) have their own credits and timeouts. Zoho's functions page says each function execution deducts one credit, and that functions exceeding their category's timeout are forcefully terminated. Timeouts listed: 10 seconds for related-list, button, validation-rule and REST API functions; 30 seconds for automation functions such as workflow, blueprint and approval; 15 minutes for scheduled functions. A single invocation is limited to 200,000 executed lines.

Daily function credits also vary by edition and user count, so a workflow that triggers a function per record can exhaust them on a large import.

Source: Zoho CRM functions: limits and quotas

What to check first (practical advice)

This section is advice from experience, not vendor documentation.

• Find out which limit you hit: credits, concurrency or timeout. The fix differs for each.
• Check how many calls your integration makes per record. Updating records one at a time costs far more than batching them.
• Spread scheduled jobs across the day instead of running them all at once.
• Look at your edition, user count and any add-on credits before assuming the limit is wrong.
• If a custom function runs per record, test it against a realistic volume, not a handful of rows.

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Skyfall Labs designs and builds Zoho integrations and automations. Because we are a Zoho Partner, treat our view with the interest we have disclosed.