An IAB Tech Lab standard that lets app publishers declare which ad networks are authorized to sell their inventory.

Where do I put the app-ads.txt file?

At the root of the developer website listed in your App Store / Google Play page, e.g. https://studio.com/app-ads.txt.

What is a Certification Authority ID?

An optional TAG-ID of the ad system, the 4th field of an app-ads.txt record.

Certification authority ID (TAG-ID)

The fourth field of an app-ads.txt line identifies the ad system with a certification authority — today that is the Trustworthy Accountability Group (TAG).

What it is

An ID that a certification authority gives to an advertising system. It is the same for every publisher of that system: all Google lines end with the same ID, all Unity lines with another one.

Examples

Google (AdMob, Ad Manager) — f08c47fec0942fa0
Unity Ads — 96cabb5fbdde37a7
Mintegral — 0aeed750c80d6423

google.com, pub-0000000000000000, DIRECT, f08c47fec0942fa0

Is it required?

The standard makes it optional, and a line without it is valid. Many networks still include it in the lines they give you — copy it as provided. Never invent one: a wrong ID is worse than none.

Where to find it

In the line your ad network gives you, in its app-ads.txt documentation, or in the network templates of our free generator — they are pre-filled and kept up to date.

Open the free app-ads.txt generator

FAQ

Is the certification authority ID the same as my account ID?

No. Your account ID is the second field and is yours alone; the certification authority ID belongs to the ad system and is shared by all its publishers.

Related guides

All app-ads.txt guides