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.
Example
google.co.ukwould be considered a root domain as "co.uk" is on the public suffix listmaps.google.co.ukwould not be considered a root domain, because "maps" is a prefixgoogle.co.ukwould 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 Ads.txt management and confirm that an a
ads.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 google.com as the domain name, with their publisher ID. For example:
google.com, pub-0000000000000000, DIRECT, f08c47fec0942fa0
google.com, pub-0000000000000000, RESELLER, f08c47fec0942fa0Publishers working with other non-Google products should list their SSP or exchange domain names, with their seller account IDs. For example:
greenadexchange.com, 12345, DIRECT, AEC242
blueadexchange.com, 4536, DIRECT
silverssp.com, 9675, RESELLERWhat 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.
My CMS doesn't let me place a file on my root domain. What should I do?
Contact your CMS provider who should provide you with the facility to host an ads.txt/app-ads.txt file on your behalf.
