# `401`- Unauthorised ## Description The call cannot be authorised due to - missing or incorrect access token - incorrect signature - missing or incorrect credentials (for /auth/token call). ## How to fix - The `details` value in the error response may contain additional information about the cause of the problem. Check whether you have provided all the information required for an authorisation check. - Check the signature creation process and ensure that it corresponds to the [guide](/products/tol/concepts/api_concepts/http_signatures). ## Example ```http HTTP/1.1 401 Unauthorised content-length: 166 content-type: application/problem+json date: Mon, 11 Oct 2021 10:42:01 GMT upvest-request-id: afcd3c2f-6965-4e1b-bb3e-87a3b481ce29 { "type": "https://docs.upvest.co/errors/unauthorised", "status": 401, "title": "Unauthorised", "request_id": "afcd3c2f-6965-4e1b-bb3e-87a3b481ce29" } ```