Types of API Credits and their limits

You can easily track your credit usage in this section. It provides a detailed breakdown showing how many credits have already been consumed and how many are still available for use.

Base credits

The number of base credits allocated to each organization depends on the edition they have purchased. These base credits may vary from one edition to another.

Variable credits

Variable credits depend on the number of agents in your organization and the plan you are using. These are added on top of your base credits to ensure your API capacity scales with your team size and usage needs.

Additional credits

If you need additional credits, you can reach out to our support team for assistance.

Concurrency and limits

In addition to API credits, Zoho Desk enforces a concurrency limit to ensure fair usage and maintain consistent service availability across all organizations. 

What is the concurrency limit

The concurrency limit in Zoho Desk refers to the maximum number of API requests that can be active (running) at the same time from a portal. This means if you have too many simultaneous requests, new ones will be rejected until some of the active ones are completed. 

You can find the concurrency credits on the API details page.

The concurrency limit applies only to OAuth-based API calls, such as those made through external integrations, SDKs, custom apps, extensions, or backend services. It does not apply to API actions triggered through the Zoho Desk web UI, meaning agent or customer activity within the Desk interface will not count toward concurrency usage.

Concurrency limits based on Zoho Desk edition

This limit is tied to the Org ID, and not to individual OAuth clients, users, or access tokens.

How the concurrency limit applies

1. Organization-wide limit
   The concurrency cap depends on the Zoho Desk edition being used. All OAuth-authenticated API requests from any client or integration count toward this limit.
   
   
2. Not applied per OAuth client or per access token
   If you use multiple OAuth clients or generate multiple tokens, they all draw from the same concurrency pool.
   
   
3. Applies to all API calls authenticated via OAuth
   Whether you call APIs using SDKs, custom apps, extensions, backend servers, or third-party integrations, every OAuth-authenticated request contributes to the limit.
   
   
4. Not applicable to the Zoho Desk UI
   Actions performed by agents or customers directly in the Desk web interface do not count toward concurrency usage. Even in large setups with hundreds of agents, UI activity will not affect your integration’s concurrency capacity.
   
   
5. Not API-specific
   The limit applies collectively across all Desk APIs. For example, simultaneous calls across Tickets, Contacts, Search, or any other module count together.

What happens if you exceed the limit

1. Incoming requests will be throttled (rejected), depending on system load.
2. API responses may indicate concurrency limit violations.
3. Normal behavior resumes automatically once ongoing requests decrease.

Zoho Desk does not enforce any request rate limits per access token. Access tokens are valid for 1 hour, after which they must be refreshed.

Allotment of API Credits

Your Zoho Desk edition comes with a fixed number of base API credits, plus additional credits based on the number of users in your account (excluding light agents). Once you’ve used up your total (base + user) credits, you can buy more, up to a maximum limit set for your edition. The table below shows the exact limits for each edition. 

Points to note when you run out of credits  

• New API requests will be denied until the next reset cycle.
• Existing automated processes that rely on APIs may stop running.
• Agents or admins will be notified if the usage reaches the predefined threshold set through API Alerts. 

You can either wait for the next reset or purchase additional credits (if available for your plan).

Additional API Credits  

If you run out of your base + user credits, you can buy more (if available for your plan). Just email support@zohodesk.com or contact your account manager.

Requirements:

• Must be the super admin
• Must be on a paid plan

A maximum of 5,000,000 (5 million) additional credits can be purchased.

Best practices

• Avoid Unnecessary API Calls – Only trigger API requests when the data truly needs to be updated or retrieved.
• Monitor Usage – Track your current API credit balance in the Zoho Desk admin console to ensure you don’t run out.