Identifying Authorized Sellers with app-ads.txt

As part of its commitment to more transparency and security in the mobile advertising ecosystem, Facebook has adopted the IAB Tech Lab's App-ads.txt Specification. It’s important both ad networks and developers do their part to participate in this movement to help remove fraud.

Like ads.txt, app-ads.txt is a text file that app devs upload to their publisher website.


An app-ads.txt record consists of a single line comprised of four fields separated by commas. The app-ads.txt record has the following fields.

Field Description Value

Ad System Domain

(Required) The canonical domain name of the advertising system to which the bidder connects.

Publisher Account ID

(Required) The identifier associated with the reseller account within the advertising system.

Your property IDs or Business ID

Account Type/Relationship

(Required) An enumeration of the type of account.


Certificate Authority ID

An ID that uniquely identifies the advertising system within a certification authority.


Example for Publishers Working with Audience Network

To add Facebook to your app-ads.txt, you have the option of using either property IDs or your business ID. In either case, you must list your developer website URL in the GooglePlay and iTunes app stores. You must have a valid developer website URL in all app stores hosting your apps.

Upload the app-ads.txt file to the root of your website domain (for example,

Adding Facebook with Property IDs

To add Facebook to your app-ads.txt with property IDs, copy and paste the following string to each of your properties. (Note: You must also update the property ID for each string.), Property ID, RESELLER, c3e20eee3f780d68

The following is an example.

[...], 1000001, RESELLER, c3e20eee3f780d68, 1000002, RESELLER, c3e20eee3f780d68, 1000003, RESELLER, c3e20eee3f780d68[...]

Adding Facebook with a Business ID

To add Facebook to your app-ads.txt with a business ID, copy and paste the following string containing your Business ID. This is the option for publishers with several property IDs., Business ID, RESELLER, c3e20eee3f780d68

For more information, see IAB Tech Lab's App-ads.txt Specification.