> [!CAUTION]
> **Caution:** This documentation is for Google Ads API **v23** . The latest active version is [**v26**](https://developers.google.com/google-ads/api/reference/rpc/latest/CustomerMatchUploadKeyTypeEnum.CustomerMatchUploadKeyType).

Enum describing possible customer match upload key types.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v23/enums/customer_match_upload_key_type.proto)

| Enums ||
|---|---|
| ## `CONTACT_INFO` | Members are matched from customer info such as email address, phone number or physical address. |
| ## `CRM_ID` | Members are matched from a user id generated and assigned by the advertiser. |
| ## `MOBILE_ADVERTISING_ID` | Members are matched from mobile advertising ids. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |