Declare authorized sellers with ads.txt/app-ads.txt

Host an ads.txt/app-ads.txt file

After you create an ads.txt/app-ads.txt file, have your webmaster upload the file to your root domain.

A "root domain" is defined as one level down from the public suffix list. The IAB specifications for ads.txt and app-ads.txt specifically ask for your file to be uploaded to the root domain.


  • would be considered a root domain as "" is on the public suffix list
  • would not be considered a root domain, because "maps" is a prefix
  • would not be considered a root domain, because "www" is a prefix.

If you have more than one root domain, an ads.txt/app-ads.txt file must be uploaded to each root domain individually.

In Ad Manager, click Admin and then Ads.txt management and confirm that an aads.txt/app-ads.txt file has been uploaded to each of your domains.

Examples of ads.txt/app-ads.txt files

Publishers working with Google products should always use as the domain name, with their publisher ID. For example:, pub-0000000000000000, DIRECT, f08c47fec0942fa0, pub-0000000000000000, RESELLER, f08c47fec0942fa0

Publishers working with other non-Google products should list their SSP or exchange domain names, with their seller account IDs. For example:, 12345, DIRECT, AEC242, 4536, DIRECT, 9675, RESELLER

What if the ads.txt/app-ads.txt file is hosted on a subdomain?

Google crawls and enforces ads.txt/app-ads.txt files placed on subdomains, where one exists, and is referenced from the ads.txt/app-ads.txt file on the root domain.

The Ad Manager ads.txt management tool does not yet show a list of crawled subdomains.

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