# Invalid Client ID when using the HubSpot API Collection for Postman **URL:** \ **Category:** APIs & Integrations\ **Tags:** timeline-and-extensions-apis\ **Created:** [May 12, 2026, 8:21pm UTC](https://community.hubspot.com/t/client-id-invalid-when-using-hubspot-api-collection-for-postman/149282 "2026-05-12T20:21:08Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![ChakS77](https://avatars.discourse-cdn.com/v4/letter/c/e95f7d/32.png) [@ChakS77](https://community.hubspot.com/u/ChakS77)\ **Post date:** [May 12, 2026, 8:21pm UTC](https://community.hubspot.com/t/client-id-invalid-when-using-hubspot-api-collection-for-postman/149282/1 "2026-05-12T20:21:08Z")
We are trying to call HubSpot API using the Collection. We created a legacy app in the HubSpot gave the relevant scope. But when we use the same to call in Postman we are constantly getting the client id is invalid. _Moderator note: I have moved your post for visibility. For reference, here is the thread where you posted: "[Hubspot API Collection for Postman](https://community.hubspot.com/t5/APIs-Integrations/Hubspot-API-Collection-for-Postman/m-p/286788#M26508)__"._ ---
**Author:** ![stassey](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/stassey/32/36_2.png) [@stassey](https://community.hubspot.com/u/stassey)\ **Post date:** [May 13, 2026, 2:25pm UTC](https://community.hubspot.com/t/client-id-invalid-when-using-hubspot-api-collection-for-postman/149282/2 "2026-05-13T14:25:13Z")
Hello @ChakS77, Welcome to the Community! To start, I would suggest looking into the linked article below as it may be able to point you in the right direction! - [OAuth Quickstart Guide](https://developers.hubspot.com/docs/apps/developer-platform/build-apps/authentication/oauth/oauth-quickstart-guide) In the meantime, I’d like to tag in some of our Top Contributors to see if they have any tips and tricks on this! Hey @SteveHTM, @Anton, @GRajput -- Do you have any suggestions for @ChakS77 on this? Thanks in advance! Best, Sam, Community Manager ---
**Author:** ![hseligson](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/hseligson/32/20940_2.png) [@hseligson](https://community.hubspot.com/u/hseligson)\ **Post date:** [May 14, 2026, 1:44pm UTC](https://community.hubspot.com/t/client-id-invalid-when-using-hubspot-api-collection-for-postman/149282/3 "2026-05-14T13:44:34Z")
Agree - I would review the OAuth docs above. Were you able to generate a token? I’d suggest using the v3 OAuth API or the latest DBV version to generate a token, and then, once you have that token, you’d use it to verify your call to whichever API you’ve granted data access to with the appropriate scopes. Here is a screenshot of my auth setup in a legacy public app, using the Sample install URL (OAuth) to generate a code, requesting a token, and then using that same token to make the API call. Here are some screenshots for reference and additional links: > **[​Generate initial access and refresh tokens - Manage OAuth access tokens using...](https://developers.hubspot.com/docs/api-reference/legacy/authentication/manage-oauth-tokens#generate-initial-access-and-refresh-tokens)** > > Was this page helpful? | Learn how to use the new v3 OAuth endpoints to manage access and refresh tokens to securely perform CRUD actions with HubSpot APIs. [![](https://d2qpr2jzcazej7.cloudfront.net/original/3X/e/2/e2e6cf3e22acc047f1ca0ac4dcc89c98be130aa4.jpeg "Postman OAuth with Carter McKay of PivIT Global") ](https://www.youtube.com/watch?v=j64kqwCvXWI) ![1275975_1_Screenshot 2026-05-14 at 9.32.40 AM.png](https://d2qpr2jzcazej7.cloudfront.net/original/3X/f/5/f5f9d9d6a497a2d89b925fbe0b1b2f0388073b4a.png) ![1275975_2_Screenshot 2026-05-14 at 9.37.56 AM.png](https://d2qpr2jzcazej7.cloudfront.net/original/3X/d/9/d9365487bdb00ca36d486b5cd82e9038ded4a856.png) ![1275975_3_Screenshot 2026-05-14 at 9.40.14 AM.png](https://d2qpr2jzcazej7.cloudfront.net/original/3X/2/8/2821060623155db2a4c8f03b04b05a3bd2431490.png) ---
**Author:** ![HPrimack5](https://avatars.discourse-cdn.com/v4/letter/h/e56c9b/32.png) [@HPrimack5](https://community.hubspot.com/u/HPrimack5)\ **Post date:** [May 13, 2026, 5:56pm UTC](https://community.hubspot.com/t/client-id-invalid-when-using-hubspot-api-collection-for-postman/149282/4 "2026-05-13T17:56:30Z")
[@SamTassey](https://community.hubspot.com/t5/user/viewprofilepage/user-id/388334) thank you for you response.. We have been following this exact documentation We are also getting success popup # Your call is authenticated A new window should open directing you back to the Postman app. If nothing happens, check to make sure your browser allows pop-ups. But when we see it on the Postman , its say Authentication failed with below response. Error: invalid\_request, Description: missing or unknown client id Our eventual aim is to call this Rest API endpoint from Oracle Integration Cloud but looks like we are unable to fix this issue on Postman. Its been more than a week. we just cannot proceed beyond this point. Any help would be appreciated. Thank You