How to fix 401 error when calling ServiceNow REST API?

[RukhsanaN]

Hi everyone,

I'm trying to call the ServiceNow REST API from an external system, but I keep receiving a 401 Unauthorized error.

Here’s what I’ve tried so far:
- Verified username and password
- Checked that the user has the “web_service_admin” role
- Tested the same credentials in Postman — still getting 401
- Ensured the instance URL is correct

Is there anything specific I need to configure under “Basic Auth” or the API user settings to resolve this issue?

Thanks in advance for your help!

[Ankur Bawiskar · Accepted solution]

@RukhsanaN 
does your instance have SSO enabled?

did you make sure the API user has this checkbox as true

Internal Integration User - True

💡 If my response helped, please mark it as correct ✅ and close the thread 🔒— this helps future readers find the solution faster! 🙏

[M Iftikhar]

Hi @RukhsanaN 
You can check this post, it explains the same 401 issue and how to fix it:
ServiceNow REST API throwing error (401 Unauthorized)

It should help you resolve the problem. 

If my response helped, please mark it as the accepted solution so others can benefit as well.

[Ankur Bawiskar · Accepted solution]

@RukhsanaN 
does your instance have SSO enabled?

did you make sure the API user has this checkbox as true

Internal Integration User - True

💡 If my response helped, please mark it as correct ✅ and close the thread 🔒— this helps future readers find the solution faster! 🙏

[Nikhil Bajaj9]

Hi @RukhsanaN ,

First thing check if web service cehck box is checked in user profile. 

Second thing - User have all REST APi related roles and the table related access which you are accessing for ex:- incident_manager in case you want to access incident access.

Third User name and password should be correct in Postman or whereever you are passing in Basic auth setting.

Forth- Endpoiunt/URL of the PDI is correct.

If it is Oauth then you need to check Token as well.

Check all these points and configure accordingly, then let us know the results.

[Nikhil Bajaj9 · Accepted solution]

Hi @RukhsanaN ,

Thanks for marking my reply as helpful. If i was able to answer your query, please mark my answer as Solution accepted.