Get Contacts by Identifiers

Use this endpoint to retrieve up to 100 contacts that match the requested identifier values for a single identifier type. `identifier_type` must be a valid identifier type: `email`, `phone_number_id`, `external_id`, or `anonymous_id`. Use this endpoint instead of the [Search Contacts endpoint](https://www.twilio.com/docs/sendgrid/api-reference/contacts/search-contacts) when you can provide exact identifiers and do not need to include other [Segmentation Query Language (SGQL)](https://www.tw...