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IAB Tech Lab Adds ads.txt Values to Help Buyers Determine the Owner and Manager of Inventory

New York, NY (April 13, 2022) – Today, IAB Tech Lab, the digital advertising technical standards-setting body, announced an update to the widely adopted ads.txt specification which they have opened for public comment for 60 days.

The update includes two new values for publishers to declare within their ads.txt files, “ownerdomain” and “managerdomain” which helps  increase the transparency into seller relationships via sellers.json and further strengthens ads.txt as a tool to reduce fraud in buying and selling of advertisements on websites, mobile apps and connected TV.

The “ownerdomain” value is used to specify the domain of the business that owns the website that the ad is being served on. This helps to connect the seller domain for PUBLISHER entries in sellers.json files, which has previously been hard to programmatically validate resulting in mismatched seller domains, especially when an entity owns multiple publisher properties.

“Owner domain provides a critical link between the business entity being paid, and listed in a sellers.json file and the ads.txt file on the site being monetized. Publicly connecting these dots closes a potential gap that allows for misrepresentation,” said Neal Richter, Chairman of the Board of Directors, IAB Tech Lab.

The “managerdomain” enables the publisher to declare the primary or exclusive monetization partner of that sites inventory. This new addition to ads.txt will help to level the supply path optimization (SPO) playing field for small to medium publishers. This is because publishers that outsource yield management, and transact under their manager’s seller ids are automatically made to appear as though they have multiple hops to access their inventory; this is a challenge when supply path optimization’s focus on buying from the fewest number of hops in the supply chain to access inventory. The addition of the Manager Domain in ads.txt will helps buyers know that even with multiple hops, this may be the most optimal route to access that publisher’s inventory.

Paul Bannister, Chief Strategy Officer of CafeMedia said, “We are excited to use the manager domain field with our publishers to give buyers more clarity that buying a given publisher through us is the most optimal path to buy that inventory. While our entries have always been in the publisher’s ads.txt file, the manager domain value provides an unambiguous link between our sellers.json entry in exchange’s sellers.json files and the publisher’s ads.txt file, providing buyers with a clear understanding of supply path.”

“Overall these two new values help to bring more transparency to the supply chain by enabling advertisers to better identify and control who their spend is going to,'” Said Shailley Singh, Vice President of Product, IAB Tech Lab. “This helps to further combat fraud, minimize the loss of revenue for advertisers, and helps to ensure spend is being directed to the right places, all of which is essential for the sustainability of our industry.”

The public comment period for ads.txt 1.1 will run through May 31, 2022, after which the IAB Programmatic Supply Chain Working Group Ads.txt Subgroup, which developed the tool, will evaluate the comments received. It will then make any necessary revisions, and release a final version. Comments are being accepted via email to

About IAB Technology Laboratory

Established in 2014, the IAB Technology Laboratory (Tech Lab) is a non-profit consortium that engages a member community globally to develop foundational technology and standards that enable growth and trust in the digital media ecosystem. Comprised of digital publishers, ad technology firms, agencies, marketers, and other member companies, IAB Tech Lab focuses on solutions for brand safety and ad fraud; identity, data, and consumer privacy; ad experiences and measurement; and programmatic effectiveness. Its work includes the OpenRTB real-time bidding protocol, ads.txt anti-fraud specification, Open Measurement SDK for viewability and verification, VAST video specification, and Project Rearc initiative for privacy-centric addressability. Board members/companies are listed at For more information, please visit

IAB Tech Lab Media Contacts

Brittany Tibaldi / Michael Vaughan
347-487-6794 / 813-210-1706 /