What do OWNERDOMAIN and MANAGERDOMAIN declare in ads.txt, and how do buyers use them?
Part of Supply path transparency
The short answer
OWNERDOMAIN and MANAGERDOMAIN are two variables added in ads.txt 1.1. OWNERDOMAIN states the business domain of the company that owns the site. MANAGERDOMAIN names a primary or exclusive sales partner, globally or for one country. Buyers compare both with the domain field in each exchange's sellers.json to tell owned, managed and resold paths apart.
Key takeaways
- OWNERDOMAIN should carry the same value as the domain field in the publisher's own sellers.json entries, written as a root domain, never a URL.
- When OWNERDOMAIN is absent, the specification says to assume the owner domain is the site's own domain.
- MANAGERDOMAIN takes a domain and an optional two letter country code, with at most one manager per country.
- A domain mismatch is a question for the publisher, since corporate domains, confidential sellers and pending verification all produce one.
- Both variables arrived with ads.txt 1.1 in 2022; IAB Tech Lab's release page says August, the specification's change log says July.
What is OWNERDOMAIN in ads.txt?
Definition
- OWNERDOMAIN
- An ads.txt variable that specifies the business domain of the business entity that owns the site or app, written once per file in the form OWNERDOMAIN=example.com.
The ads.txt 1.1 specification (opens in a new tab) gives the example that example.com owns example1.com and example2.com. Each of those sites would carry the same line, so a buyer reading three different files can see that one company sits behind all of them. The specification ties the value to the exchange side of the record: it should be the same value as the domain in this publisher's entries in the sellers.json files its ads.txt references.
| Rule | What the specification says | Slip to avoid |
|---|---|---|
| Format | Public Suffix List plus one, not a full hostname or a URL | Writing www.example.com or https://example.com |
| Repeats | If more than one instance is included, only the first should be used | A second, newer line added at the bottom that crawlers ignore |
| When owner and site match | Recommended even if the owner domain is the domain hosting the file | Leaving it out because it seems redundant |
| When it is missing | Assume the owner domain is the domain being monetized | A group owned site that omits it reads as its own owner |
| Complete supply chains | The first node's sellers.json domain should match OWNERDOMAIN | A first node registered under a different corporate domain |
The format rule borrows from the Public Suffix List (opens in a new tab), which defines where a registrable domain begins. For a Canadian site, news.example.ca and www.example.ca both reduce to example.ca, so the variable carries example.ca. The specification also asks buyers to require sellers listed as BOTH in sellers.json to list OWNERDOMAIN correctly in every file they own or represent, because those sellers mix owned and resold inventory under one name.
What is MANAGERDOMAIN in ads.txt?
Definition
- MANAGERDOMAIN
- An optional ads.txt variable that specifies the business domain of a primary or exclusive monetization partner, for all markets or, with a country code, for one market.
The specification says to use it only when the owner of the site does not manage monetization globally or in a specific country, and only for a seller that is not the publisher but is the primary or exclusive programmatic seller for the site. Its syntax is a root domain followed by an optional ISO 3166-1 alpha-2 country code; a blank code means global. A global line carries no country, and a line with a country overrides the global default for that market.
That country option matters for cross-border planning. A site might handle its own sales at home and hand Canadian demand to a sales house, which it declares with a line such as MANAGERDOMAIN=northsales.example, CA. The specification allows more than one MANAGERDOMAIN value, but only one per country, and IAB Tech Lab's implementation guidance (opens in a new tab) says conflicting entries for the same country will likely be ignored. A buyer planning Canada reads the CA line first, then the global line.
How do OWNERDOMAIN and MANAGERDOMAIN help buyers?
Neither variable authorizes anyone; the seller lines still do that. What they add is identity: a buyer can connect an account in an exchange's sellers.json to the company that owns or manages the site, which sellers.json alone cannot do when a business sells under a name unrelated to its websites.
Four buyer uses for the ads.txt 1.1 variables
- Group a list by owner. Sites sharing one OWNERDOMAIN belong to one company. Counting them together shows how much of a plan depends on one owner, a question the guide to publisher concentration works through.
- Separate owned from resold inventory. For a seller listed as BOTH, an entry whose domain equals the site's OWNERDOMAIN is the owner selling its own pages; a BOTH seller on another owner's site is reselling.
- Check the start of a complete chain. When a bid request's SupplyChain object is marked complete, the first node's sellers.json domain should equal OWNERDOMAIN, or MANAGERDOMAIN for managed inventory.
- Find the managed path for a market. A MANAGERDOMAIN line for the plan's country identifies the partner the implementation guidance treats as the most direct route, even though its path has an extra hop.
What if OWNERDOMAIN does not match sellers.json?
Treat it as an open question, not a finding. Several ordinary situations produce a mismatch, and IAB Tech Lab's FAQ for sellers.json and the SupplyChain object (opens in a new tab) frames these records as information that consumers should verify, not as guarantees of correctness. Work through the likely causes before deciding anything about the path.
| Situation | What you see | What to ask or check |
|---|---|---|
| The variable is missing | No OWNERDOMAIN line, so the site's own domain is assumed, while sellers.json shows the parent company | Ask the publisher to add OWNERDOMAIN with the parent's domain |
| The seller is confidential | is_confidential is 1, so sellers.json may omit name and domain | Nothing to compare; ask the exchange or publisher to confirm the account |
| No web presence or pending verification | The sellers.json domain is blank; Google says a business domain may stay hidden until it verifies the seller owns the URL | Recheck later; confirm the account with the publisher meanwhile |
| A different corporate domain | The owner sells under a holding company or a subsidiary's domain | Ask which entity is paid; one of the two records needs updating |
| The seller is a manager | The domain equals MANAGERDOMAIN, not OWNERDOMAIN | Expected for managed inventory; confirm the country code fits the plan |
| None of the above | An unrelated domain on a line labeled DIRECT | Hold the path and ask the publisher who controls the account |
When did ads.txt 1.1 add these variables?
In 2022. The change log in the specification lists version 1.1 with an April 2022 public comment and a July 2022 final release, and describes it as adding the managerdomain and ownerdomain variables. IAB Tech Lab's ads.txt 1.1 implementation guide (opens in a new tab) carries a released August 2022 date, the same month the Tech Lab release page gives. Earlier versions had already added CONTACT and SUBDOMAIN in 2017 and INVENTORYPARTNERDOMAIN in 2021.
Version 1.1 changed no existing rule. The specification says there have been no breaking changes since ads.txt was created in 2017 and asks crawlers to support new variables as they appear rather than read a version number. A file written before 2022 is still valid; it simply cannot state an owner or manager, so a buyer falls back on the assumption that the site owns itself.
What does an OWNERDOMAIN review look like on a real plan?
Fictional example
A children's museum in Virginia
A fictional children's museum in Richmond wants to sell family memberships across Virginia, from Northern Virginia to Norfolk, and its agency builds an English-language display plan beside parenting, family events and local news sites. The planner reads the variables in each of 24 candidate files before the deal is set up.
Five sites share OWNERDOMAIN=familymedia.example, so the planner counts them as one owner and caps their share of the budget. Their sellers.json entries on two exchanges list the same domain as PUBLISHER, so those paths are the owner's own.
A family events site declares MANAGERDOMAIN=citysales.example, US. On its exchange, sellers.json lists the seller for that path as INTERMEDIARY with the sales house's domain, which fits a managed path for a US plan. A parenting blog has no OWNERDOMAIN, and its DIRECT seller's sellers.json domain belongs to an unrelated company. The planner holds that path and asks the blog's editor who controls the account.
How does PlacementGraph show who owns and sells each site?
PlacementGraph reads each site's ads.txt and the exchanges' seller directories, and shows sites that share an owner's ad or analytics codes once.
Frequently asked questions
Do OWNERDOMAIN and MANAGERDOMAIN work in app-ads.txt?
Yes. The specification describes OWNERDOMAIN as the business domain of the entity that owns the domain, site or app, and IAB Tech Lab's implementation guidance covers ads.txt and app-ads.txt together. For an app, the variables sit in the app-ads.txt file on the developer website named in the store listing.
Does a MANAGERDOMAIN line replace the manager's seller lines?
No. The variable only names the manager. The manager's accounts still need their own seller lines, and in the implementation guidance's managed example the file lists the owner's account on the manager's system as DIRECT and the manager's exchange account as RESELLER, next to the MANAGERDOMAIN line.
Should a sales house be listed in OWNERDOMAIN?
No. OWNERDOMAIN names the business that owns the site, and only the first instance in a file is read. A sales house belongs in MANAGERDOMAIN when it is the primary or exclusive programmatic seller, or simply in RESELLER lines when it is one of several partners.
How is MANAGERDOMAIN different from INVENTORYPARTNERDOMAIN?
The implementation guidance says a manager sells a publisher's inventory, usually for a revenue share, and appears in the supply chain. INVENTORYPARTNERDOMAIN names a company that owns or has rights to sell part of the ads in an app or site under an inventory sharing agreement, for example in CTV, and is expected to be the final payee.
Sources
- ads.txt Version 1.1 specification (opens in a new tab)IAB Tech Lab, 2022 (GitHub)
- Ads.txt Implementation Guidance (ads.txt 1.1) (opens in a new tab)IAB Tech Lab (GitHub)
- ads.txt 1.1 Implementation Guide (opens in a new tab)IAB Tech Lab, released August 2022
- sellers.json specification (opens in a new tab)IAB Tech Lab (GitHub)
- Provide seller information with sellers.json (opens in a new tab)Google, Ad Manager Help
- FAQ for sellers.json and SupplyChain Object (opens in a new tab)IAB Tech Lab, July 2019, updated September 2020
- Public Suffix List (opens in a new tab)Mozilla Foundation, publicsuffix.org
Researched and written by PlacementGraph Research. Read how we research, source and update these pages. Corrections: diana@placementgraph.com.