20153: Invalid Issuer Or Subject

This error occurs when the issuer or subject of the JSON Web Token provided to the Twilio API is invalid.

For Public Key Client Validation, the iss claim must be an API Key SID and the sub claim must be the Account SID.

• The iss claim is missing.
• The issuer entity (API Key) is suspended in Twilio.
• The sub claim is missing.
• The subject entity (account) is suspended in Twilio.
• The API Key SID in iss is not associated with the Account SID in sub.

• If using Public Key Client Validation, ensure the account and the API key are valid and not suspended.
• Verify that both iss and sub claims are present and correctly set: API Key SID in iss and Account SID in sub.
• Confirm that the API Key used to sign the token is associated with the specified account.
• If needed, validate that the token is structurally sound using standard JWT tooling.

• Public Key Client Validation Quickstart
• Get Started with Public Key Client Validation
• REST API: Credentials