API Call Limits

• Concurrency Limits: These vary by edition, ranging from 5 concurrent calls for the Free edition to 25 for the Ultimate/CRM Plus edition2.

• Sub-Concurrency Limits: For specific APIs like Insert, Update, or Upsert records (when more than 10 records are involved), the sub-concurrency limit is 10 across all editions2.

• Credit System: Each API call consumes credits, with some operations requiring more credits than others. For example, the "Convert Lead" API consumes 5 credits per call2.

Bulk Write API Limitations

• File Size and Format: Only one zipped CSV file can be uploaded per request, with a maximum size of 25 MB. The system supports only comma, semicolon, colon, and pipe delimiters1.

• Unsupported Fields: Fields like File Upload, Image Upload, Created By, Modified By, Created Time, Modified Time, Formula Fields, Auto Number, and Campaigns integration are not supported for bulk write operations1.

• Unsupported Modules: Attachments, Notes, Events, Calls, and record images are not supported by the Bulk Write API1.

Record Limits

• Insert/Update/Upsert: You can insert, update, or upsert a maximum of 100 records per API call2.

• Add/Remove Tags: You can add or remove tags from a maximum of 500 records per API call2.

Function Limits

• Lines of Execution: Functions can execute up to 200,000 lines6.

• Response Limit: The response size from a function is limited to 10 MB6.

• Send Mail: You can send up to 50,000 emails per day using the send mail syntax in functions6.

Error Handling

Common errors include invalid module names, invalid data types, duplicate data, missing mandatory fields, authentication failures, and invalid OAuth scopes5.

These limitations are crucial for planning and optimizing API usage in Zoho CRM to avoid hitting these constraints and ensure smooth data management and integration processes.