---
page_type: error
code: 20153
message: "20153: Invalid Issuer Or Subject"
level: ERROR
product: Platform
---

## Error - 20153

### Invalid Issuer Or Subject

The issuer or subject of the JWT provided to the Twilio API was invalid.

#### Possible Causes

- The issuer is missing from JWT
- The issuer entity is suspended in Twilio.
- The subject is missing from JWT
- The subject entity is suspended in Twilio.
- The issuer and subject are not related.

#### Possible Solution:

- In case of Public Key Client Validation, make sure the account and the API key are valid and not suspended.
- For the details on JWTs used as part of Public Key Client Validation, see [the documentation](/docs/api/credentials/public-key-client-validation-getting-started)
- To check whether the JWT is structurally correct, you can use the tools available at jwt.io.