# Error Code | Error Code | API | Reason | | ----------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------- | ------------------------------------------------------- | | 400 | Token | Same authcode in the body is being re-used. | | Authcode error - missing, invalid, expired, revoked. | | | | 401 | Token | No security header given | | Invalid App ID used. Digital service is not registered with Verify | | | | The timestamp of server is not synchronised. Check timestamp of server. | | | | The value of the nonce in the authorisation header was deemed to be repeated. Check that the nonce is not re-used | | | | Ensure HTTP 'Authorization' header to be 'PKI\_SIGN' | | | | Person | No security header given (HTTP 'Authorization' header) | | | Invalid App ID used. Digital service is not registered with Verify | | | | The timestamp of server is not synchronised. Check timestamp of server. | | | | The value of the nonce in the authorisation header was deemed to be repeated. Check that the nonce is not re-used | | | | Ensure HTTP 'Authorization' header to be 'PKI\_SIGN' | | | | The requested UIN/FIN does not match the UIN/FIN of the person who logged in | | | | Requested attributes do not match the attributes consented by person | | | | 403 | Token | Incorrect API URL used. | | Person | Incorrect API URL used. | | | Digital service is not registered with Verify. | | | | Request contains attributes not allowable for the digital service. | | | | 404 | Person | Missing Myinfo profile. | | 500 | Token | Unexpected error. Check response body for actual error. | | Person | Unexpected error. Check response body for actual error. | | --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.developer.singpass.gov.sg/docs/legacy-verify/error-code.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.