Authorized Digital Sellers


Authorized Digital Sellers for web (ads.txt) is an Interactive Advertising Bureau (IAB) Tech Lab initiative to improve transparency in programmatic advertising by allowing publishers to identify who is authorized to sell their inventory. Declaring authorized sellers in an ads.txt file helps protect buyers and sellers from misrepresented inventory. The files are publicly available and crawlable by exchanges, Supply-Side Platforms (SSPs), Demand-Side Platforms (DSPs), and other buyers and third-party vendors.

Authorized Sellers for apps (app-ads.txt) is an extension to the Authorized Digital Sellers standard. It expands compatibility to support ads shown in mobile apps and Connected TV (CTV).

To learn more, see ads.txt and app-ads.txt guidance from IAB Tech Lab.

Topics in this article

Publisher participation

A publisher is considered to be participating if their inventory has an associated ads.txt file:

  • For Web-based inventory (Example:
    • You’ll be able to access the ads.txt file from the root domain at
  • For App-based inventory:
    • You can find the developer’s website listed on the app store via the developer website URL noted for the app. You can access the app-ads.txt file on the developer’s website at 
    • Supported stores include: Google Play Store, Apple Stores, and other app stores that use meta tags that allow the store to be crawlable.
Note: This applies for mobile and TV/CTV apps. Non-participating publishers won’t have an associated ads.txt or app-ads.txt file. While an ads.txt or app-ads.txt isn't mandatory, it's highly recommended.

CTV devices that don't support app-ads.txt are treated as non-participating and will bid regardless of the advertiser's targeting criteria.

Display & Video 360 excludes unauthorized sellers for web, mobile, and TV inventory. You can purchase inventory from non-participating publishers at your own risk by updating the inventory source targeting option in your buying policy.

Seller authorization

Display & Video 360 checks that every seller, including intermediaries,  identified in the SupplyChain object is authorized by the publisher by checking the publisher’s ads.txt/app-ads.txt files and automatically excludes inventory from unauthorized sellers to prevent bidding on unauthorized web, mobile, and/or CTV inventory. This protects you from buying inventory from potentially unauthorized sources.

The following are definitions for authorized sellers and unauthorized sellers: 

  • Authorized sellers are categorized as either direct or resellers, depending on whether the seller owns or resells the monetized inventory. Their seller ID has been declared in the ads.txt/app-ads.txt file to authorize selling inventory.
  • Unauthorized sellers aren't declared in the ads.txt/app-ads.txt file for the monetized inventory. These sellers are blocked to protect you. Monetized inventory resold by unauthorized sellers is also blocked. This is achieved by checking the authorization of all sellers and intermediaries identified in the SupplyChain object for the inventory.
Note: An empty SupplyChain object is considered unauthorized.

Declaring Authorized sellers

Publishers can declare a row in the ads.txt or app-ads.txt file to specify who is authorized to sell their inventory with the following fields :

  • Exchange/SSP domain name: Enter the domain name of the exchange or supply side platform (SSP) you’re authorizing to sell inventory. For example:
  • Exchange-specific publisher ID: Enter your unique publisher account ID. For example: pub-0000000000000000.
  • Account/relationship type: Use one of the following categories to define the seller’s account or relationship type:
    • DIRECT: The seller directly owns the inventory being monetized.
    • RESELLER: The seller resells inventory owned by another entity.
  • (Optional) Certification authority ID: Enter an optional identifier for the advertiser system within a certification authority. For example, f00a00bcd0000ef0.

Sample ads.txt or app-ads.txt declaration

The following declaration contains 4 rows of declarations to authorize the following exchanges/SSP to sell inventory:,,, and, pub-0000000000000000, DIRECT, f08c47fec0942fa0, 12345, DIRECT, AEC242, 4536, DIRECT, 9675, RESELLER

Ineligible inventory

Digital out-of-home inventory isn’t covered by ads.txt or app-ads.txt specification.

You may not be able to see authorized seller targeting options for some line item types which exclusively target inventory for which ads.txt or app-ads.txt restrictions don’t apply.

Inventory sharing

Inventory sharing is when an inventory publisher (a website, app, or CTV channel host), shares monetization rights for ad inventory with multiple partners through a distribution agreement.

Inventory publishers can control their ad space and brand by declaring who can and can’t represent their brand using the optional inventorypartnerdomain specification within the app-ads.txt file:

  • The inventorypartnerdomain field contains the domain of the inventory sharing partner whose authorized to sell the inventory. Buyers can use this to validate authorized resellers when checking the app-ads.txt file of the publisher.


An inventory publisher who hosts a CTV channel can declare an inventory relationship with a partner, SamplePartner, a content owner who shares rights to sell ads owned by the publisher.

The shared CTV inventory would contain an app-ads.txt file that points to a partner’s ads.txt file or app-ads.txt file through the inventorypartnerdomain field:

The SSP also passes the inventorypartnerdomain field in bid requests to Display & Video 360. When both requirements are met, Display & Video 360 looks at the partner’s ads.txt or app-ads.txt file to check for authorized sellers to protect you from fraud and increase transparency.

To learn more about CTV app-ads.txt specifications, see Guidance for Inventory Sharing (in CTV/OTT & Beyond) from IAB tech lab.

Authorized seller targeting in Display & Video 360

Display & Video 360 allows buyers to apply ads.txt and app-ads.txt targeting options at the partner, campaign, insertion order or line item level. Ads.txt and app-ads.txt targeting options for new entities inherit the settings applied on the parent entity. For example: a new line item would inherit the settings you apply on a parent entity, such as an insertion order, to which that line item belongs.

The following targeting options are available:

  • Authorized Direct Sellers and Resellers: All authorized sellers, including those that directly own or resell the inventory being monetized, as indicated by a DIRECT or RESELLER declaration in the ads.txt and/or app-ads.txt file respectively. This is the default option for new Display & Video 360 campaigns
  • Authorized Direct Sellers only: Only authorized sellers that directly own the inventory being monetized, as indicated by a DIRECT declaration in the ads.txt and/or app-ads.txt file.
  • Authorized and Non-Participating Publishers: All authorized sellers, including publishers that have not posted an ads.txt and/or app-ads.txt file. Display & Video 360 evaluates entries in an ads.txt or app-ads.txt file to determine whether a seller is properly declared. Undeclared sellers are deemed unauthorized and are blocked to protect you.

By default, web and mobile app inventories are set to include Authorized sellers only.

You can change your authorized seller targeting option by adjusting the inventory source quality setting in your buyer policy at the line item level, insertion order level, campaign level, partner level, or as a bulk update by uploading an SDF file.

Note: Authorized seller targeting options may not be available for line items that exclusively target ineligible inventory. Authorized seller targeting options only apply to web-based, mobile app, and Connected TV inventory.

If you have to set separate inventory source quality policies for app and web inventory, consider temporarily using separate line items when buying web and app inventory.

To update an inventory source targeting option

  1. Navigate to insertion order or line item details.
  2. Under Inventory source:
    • For Quality: Choose an authorized seller targeting option.

Bulk update inventory source targeting option 

  1. Navigate to the advertiser level.
  2. Go to Resources > Brand controls.
  3. Choose View breakdown to see a breakdown of the brand control setting.
  4. Choose Actions > Download to export the SDF file to view line items that would potentially be impacted by modifying the app-ads.txt file. 
  5. Open the SDF file and update the Inventory Source Targeting - Authorized Seller Options column based on your inventory buying policies:
    • Authorized and Non-Participating Publisher: Choosing this option allows you to purchase from both authorized and non-participating publishers when your campaign inventory is limited.
    • Authorized Direct Sellers: Choosing this option allows you to purchase from authorized direct sellers only.
    • Authorized Direct Sellers and Resellers: Choosing this option allows you to purchase from either authorized direct sellers or resellers.
      Important: Choosing Authorized and Non-Participating Publisher increases your inventory quality risk. Consider only setting this temporarily for private deals. We recommend encouraging publishers to adopt app-ads.txt for better transparency.
  6. Once you’ve saved your changes, choose Actions > Upload to upload your changes.

Authorized seller bidding in Display & Video 360

Web, Mobile App, and Connected TV inventory

Has ads.txt/app-ads.txt? Seller status Targeting status Does Display & Video 360 bid?*
Yes Unauthorized N/A No
Yes Authorized Direct
Authorized and Non-Participating Publishers Yes
Authorized Direct Sellers and Resellers Yes
(Default**) Authorized Direct Sellers only Yes
Yes  Authorized Reseller Authorized and Non-Participating Publishers Yes
Authorized Direct Sellers and Resellers Yes
(Default**) Authorized Direct Sellers only No
No Non-Participating Authorized and Non-Participating Publishers Yes
Authorized Direct Sellers and Resellers No
(Default**) Authorized Direct Sellers only No

* Other bid rejection reasons may apply
**The default value is set at the partner level. This can be overwritten at the campaign, insertion order, or line item level. This default applies to web and mobile app inventory. 

Authorized seller reporting in Display & Video 360

In Display & Video 360 you can use the Authorized Seller state dimension to report on the ads.txt and app-ads.txt participation or authorization status of inventory bought. The Authorized Seller state dimension categorizes inventory into Authorized Direct Sellers, Authorized Resellers, Non-Participating Publishers, and Ineligible. Learn more about publisher participation and seller authorization.

The reach impact of ads.txt and app-ads.txt targeting options can also be estimated using the Inventory Availability report. Learn more about how Display & Video 360 calculates potential reach.

Frequently asked questions

What can I do to minimize the impact of Authorized Seller targeting on my campaign delivery?

You can expand the reach of authorized web/app inventory (recommended), or consider adjusting your authorized seller targeting options based on your inventory quality preferences.

Expand reach of authorized app inventory (recommended)

  • Expand inventory source targeting to include more authorized app inventory and use reach forecasts or Inventory Availability reports to estimate incremental reach. Target Open Auction for broader app-ads.txt coverage, explore the Marketplace or work with publishers to recommend premium authorized app inventory.
  • If targeting channels, use App/URL suggestions to find brand-safe app inventory to expand channel reach.
  • If inventory source targeting cannot be expanded, for example: for private deals, encourage publishers to adopt app-ads.txt on the desired inventory.
You can update your inventory source targeting option if your campaign inventory is limited to purchase inventory from non-participating publishers at your own risk.

How does app-ads.txt enforcement affect campaign delivery?

The enforcement of app-ads.txt by Display & Video 360 does not currently impact TV apps without an app-ads.txt file. Display & Video 360 will only stop buying unauthorized TV app inventory (TV apps that have an associated app-ads.txt file in which the seller's publisher ID is not declared).

How can I improve ads.txt adoption on desired web or app inventory?

Ads.txt/app-ads.txt files need to be posted by the publisher. Publishers can reference the following setup FAQs and work with their website administrator to ensure their files can be crawled by Google.

How does the Authorized Seller targeting option affect app-based inventory?

The Authorized Seller targeting options affect web-based, mobile app, and CTV inventory. 

  • The default for web and mobile app inventory at the partner level is set to Authorized Sellers only. This can be changed at any time.

How can I assess the impact of Authorized Seller targeting on campaign reach?

You can estimate the reach impact of applying ads.txt/app-ads.txt targeting options by using Reach forecasts or the Inventory Availability report.

How can I troubleshoot the impact of Authorized Seller targeting on campaign spend?

For eligible inventory, you can check the Targeting section of the deal troubleshooter to determine if a significant percentage of bid requests are filtered due to Authorized Seller state. Learn more about the Troubleshooting your deals.

Why does Display & Video 360 show a domain/app as non-participating, although it has an ads.txt or app-ads.txt file?

For Display & Video 360 to categorize a domain or app as participating, the ads.txt or app-ads.txt file must be discoverable by the Google crawler and be posted according to the IAB Tech Lab specification.

For apps specifically, publishers must:

  • Register the app with the Google Play or App Store for mobile apps or with Android TV or similar TV store for CTV apps
  • >Include a valid developer website in the Google Play or App Store listing for mobile apps or with Android TV or similar TV store for CTV apps
  • Make sure that the app-ads.txt file is accessible from the root domain or a valid subdomain.When applicable, the app-ads.txt file for CTV inventory may also point to an inventory sharing partner’s ads.txt file through the inventorypartnerdomain. The SSP will also have to pass on the inventorypartnerdomain field in bid requests to Display & Video 360.

Why is the Authorized Seller targeting option not visible on some line items?

The Authorized Seller targeting option may not be visible on some Line Item types which exclusively target ineligible inventory by default, or inventory for which ads.txt or app-ads.txt enforcement does not apply. Learn more about ineligible inventory.

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