# {"reason":"Invalid Token!","error":"invalid\_grant"} error when refreshing access token

**URL:** <https://devforum.zoom.us/t/reason-invalid-token-error-invalid-grant-error-when-refreshing-access-token/127541>\
**Category:** Authentication\
**Created:** [February 19, 2025, 12:57pm UTC](https://devforum.zoom.us/t/reason-invalid-token-error-invalid-grant-error-when-refreshing-access-token/127541 "2025-02-19T12:57:36Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Mykyta](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mykyta/32/67342_2.png) [@Mykyta](https://devforum.zoom.us/u/Mykyta)\
**Post date:** [February 19, 2025, 12:57pm UTC](https://devforum.zoom.us/t/reason-invalid-token-error-invalid-grant-error-when-refreshing-access-token/127541/1 "2025-02-19T12:57:36Z")

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**API Endpoint(s) and/or Zoom API Event(s)**  
Endpoint: [https://zoom.us/oauth/token](https://zoom.us/oauth/token)  
Method: POST  
Authorization header: Convert.ToBase64String(Encoding.UTF8.GetBytes($“{\_zoomOptions.ClientId}:{\_zoomOptions.ClientSecret}”));  
Body:  
x-www-form-urlencoded  
grant\_type=refresh\_token&refresh\_token=\<refresh token issued 1-2 hours ago\>

**Description**  
Our platform uses Zoom API to create meetings on behalf of a user. When the user establishes an integration, we receive a valid access token that can be used to create events on behalf of the user.

**Error**  
When we try to refresh the token with the refresh token issued 1-2 hours ago, we receive the `{"reason":"Invalid Token!","error":"invalid_grant"} error`. I double-checked all the credentials. The code has not been changed since 2023

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**Author:** ![Fario\_Consulting](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@Fario\_Consulting](https://devforum.zoom.us/u/Fario_Consulting)\
**Post date:** [February 19, 2025, 8:47pm UTC](https://devforum.zoom.us/t/reason-invalid-token-error-invalid-grant-error-when-refreshing-access-token/127541/2 "2025-02-19T20:47:38Z")

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Hi,

Most likely the refresh token being used is no longer valid. Could you try to reauthorize the app and obtain a brand new bearer token and refresh token.

Cheers,  
Harsh  
[Fario Consulting](https://farioconsulting.com)

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<div class="post-metadata">

**Author:** ![Mykyta](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mykyta/32/67342_2.png) [@Mykyta](https://devforum.zoom.us/u/Mykyta)\
**Post date:** [February 20, 2025, 11:45am UTC](https://devforum.zoom.us/t/reason-invalid-token-error-invalid-grant-error-when-refreshing-access-token/127541/3 "2025-02-20T11:45:58Z")

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We discovered that users can have only one access/refresh token pair per Zoom application. When the same user requests a new access/refresh tokens pair, the previous one expires instantly. I haven’t found mentions of this behavior in the documentation