# Common Pay API Headers

All Pay APIs require specific information to be sent in the header of every request. Some requests require additional information.

## Required Header Fields for all Pay APIs

Travelport recommends as best practice that all the following header fields be sent with all requests:

- Accept: application/json
- Content-Type: application/json
- Authorization: Bearer token from the generated [Oauth token](/docs/getting-started/authentication).
- XAUTH_TRAVELPORT_ACCESSGROUP: Each PCC is associated with a unique access group. Your PCC and access group are included in the welcome letter sent when you are provisioned for any Travelport TripServices API.
  - Accept-Version: Version number of the API, e.g., 11, 11_1
  - Content-Version: Version number of the API, e.g., 11, 11_1


## Pay Response Headers

Note that the following fields are returned by the Pay APIs in the response headers. No customer action with these is necessary:

• Date: Returned in GMT

• Content-Type: application/json

• E2ETrackingId: Unique identifier returned for every transaction

• Content-version: 11, 11_1(version number of the API)

• Vary: accept-encoding

• Content-Encoding: gzip

• Transfer-Encoding: chunked