Ads.txt Publisher Manual: A Guide To Implementation

AdTech Industry Definitions

Here’s a quick overview of the Ads.txt implementation process:

Step 1: Gather all the necessary information from your accounts with resellers, network partners, and parties that make your inventory available to buyers. This includes the domain name of the advertising system, Publisher account IDs, account relationship types (direct or reseller) and if available, the certification account ID for verified advertising systems.

Step 2: Create the ads.txt file in notepad or any other document creation software according to the specifications set out by the IAB. Save and name the file ads.txt.

Step 3: Upload the file in the root of your domain and not a subdomain as subdomains are not currently supported. An example would be Keep in mind that this URL string is just an example and visiting the URL will yield no result. Uploading the text file to your website should be self-explanatory, however, if you do not know how to do it get your webmaster to perform the task for you.

For help with your ads.txt setup & any other ad optimization issues, sign up for a Profesional account at MonetizeMore today!


The programmatic advertising industry is full of fraud. It’s unfortunate, startling and nothing but the truth. Earlier this year CNBC published an article stating that advertisers might be looking at an estimated loss of over $16.4 billion for 2017 compared to $12.5 billion in 2016 thanks to fraudulent traffic. Companies, The&Partnership and Adloox, partnered and looked at billions of bid requests to bring the statistics to light.

Defining the exact numbers when it comes to online advertising fraud is difficult. There are many different sources also estimating varying levels of ad budgets lost due to fraud.

Fraud is and remains an ever-present problem in the industry. Thankfully, organizations like the Interactive Advertising Bureau (IAB) exist who use their resources to improve and implement standards for the good of the online advertising industry.

example ads.txt subdomainThey’ve come up with a solution for all the fraudulent online activities taking place called the Authorized Digital Sellers project or Ads.txt for short. This method of battling bot traffic that ends up viewing and clicking on ads instead of real humans is simple, secure, and the implementation for publishers is not all that hard.

Although adoption within the premium publisher realm seems to be moving slow, implementing it as a publisher is important and there are rumors swirling that ads.txt will become mandatory by Q4 of 2017.

Here at MonetizeMore, we’ve had many inquiries from publishers asking us how to implement ads.txt on their website properties so; we decided to create the ultimate Ads.txt implementation manual. This way we can support all internet publishers, not only those working with MonetizeMore and work together towards a transparent, non-fraud stricken online advertising industry.

If you’re looking to manage your Ads.txt file via WordPress, install our free Ads.txt WordPress Plugin.

What is ads.txt?

amazon ads.txt dfp combination fileNow that you’ve got an overview with regards to why the industry needs something to combat fraud let’s quickly discuss what it is. It is a simple text, or .txt file publishers upload to their website properties where they declare in front of the whole world which parties within the advertising industry they allow selling their ad inventory.

They create a list of “Authorized Digital Sellers” (ads.txt abbreviation) which can be referenced by programmatic advertisers/buyers when purchasing advertising inventory from sellers.

What’s great about this solution is the fact the publishers have full control since they should be the only entities who have access to their domain and hosting root to upload the ads.txt file.

The Interactive Advertising Bureau is aware of the fact that publisher not only market their ad inventory through one particular channel and the ads.txt file is design to support that.

The following publisher inventory selling is supported via:

  • Ad exchanges through personal accounts
  • Ad networks who sell as programmatic partners
  • Content syndication partnerships

Ads.txt benefits for publishers & the advertising industry

google adsense ads.txt for bloggerFraud gives the online advertising industry a bad name. It decreases advertiser trust and ultimately affects everyone. If you have been wondering whether or not as a publisher you should adopt the IAB ads.txt within your business model let me show you some of the benefits it provides.

As you’ll see in the next section, creating the ads.txt sample file is not rocket science. Since it’s in a simple format, that of the ads.txt file, it can easily and quickly be updated to present any changes within your business.

All the information you need to create the ads.txt file isn’t hard to come by since most systems already present the information with regards to the OpenRTB protocol.

Implementing these practices from IAB provides transparency into who is selling what ad inventory and whether they are doing it legitimately. This increases advertiser confidence in your ad inventory.

Let me explain the last point like this: Buyers frequently can’t tell which parties are selling impressions in ad exchanges. Also, sometimes the URL delivered does not even accurately represent the party selling and delivering the impression. The OpenRTB protocol already includes Publisher and URL ID’s, but no record exists that tells who owns particular publisher ID’s and how valid that information is.

Upon implementation of the file buyers will be able to determine who the Authorized Digital Sellers are for the publisher and confidently purchase media without doubting the inventory’s authenticity.

How to create and implement ads.txt?

Here is the official implementation guide from the Interactive Advertising Bureau: IAB Tech Lab Ads.txt Specification Version 1.0

Instructions from Google for the adoption of the technology (whether running AdSense, Ad Exchange or DFP) is on this page: Declare authorized sellers with ads.txt

Find out how to create your ads.txt AdSense code here: 

Alternatively, you can watch this video from Google Publisher University. Take note that the video is for Google-owned products only.

Here is an in-depth explanation of the ads.txt file compilation:

Each line of text within the ads.txt spec file contains between 3-4 fields of information which the first three fields are required. Here’s an example:

<FIELD #1>, <FIELD #2>, <FIELD #3>, <FIELD #4>

As mentioned, Field 1 – Field 3 is mandatory whereas Field 4 is optional.

The following excerpt from the IAB official document explains each field and its purpose in detail.

IAB ads.txt document screenshot

As a publisher, it will end up looking like this:

#< SSP/Exchange Domain >, < SellerAccountID >, < PaymentsType >, < TAGID >

Different situations require different ads.txt setups as not all publishers sell inventory the same way. Three example cases exist as shown below:

Single System Direct

In this instance, you as a publisher only sell your inventory via a single system that you control. Here’s an ads.txt example according to the Interactive Advertising Bureau:

Single System Direct

Single System Reseller

Here, very similar to “Single System Direct,” you as a publisher only sell your inventory via a single system, but instead of controlling it, an independent company manages the reselling of your inventory. In the example below the fourth field got excluded as the reseller was not verified independently. Here’s an ads.txt example according to IAB:

Single System Reseller

Multiple resellers and systems

This example is a combination of the previous two where more than one “single system direct” and “single system reseller” are used. Some advertising systems are verified and thus can add “field #4” at the end of the line of text with their Certification Authority ids. Here’s an example according to IAB:

Multiple resellers and systems

In closing

We hope you’ve realized that implementing ads.txt as a publisher is not as hard as you might have initially thought. Now it’s your turn to go out, follow the instructions given, and get the file uploaded to your website properties.

If you are having any issues implementing Ads.txt or have questions, you can contact the MonetizeMore support team here.

Sign up for a Professional account at MonetizeMore to learn how Ads.txt fits into an optimal ad optimization strategy.

Additional FAQ

What is an ads.txt file?

Ads.txt or “Authorized Digital Sellers” is a technical specification developed by the IAB to combat ad fraud. Publishers upload a simple text file to their website to declare which sellers are authorized to sell their ad inventory.

Is ads.txt mandatory?

Ads.txt is not mandatory, but most network partners/resellers recommend that publishers have the file available. It increases the trustworthiness of the publisher’s ad inventory.

How do I create an ads.txt file on my website?

Create a text file called ads.txt and present the following information per line. Information you need to display includes the domain name of the network partner/reseller, Publisher account ID, account relationship (direct or reseller), and the certification account ID. We provide more examples in our blog post.

How do I upload a TXT file to ads?

Once you've created your ads.txt file, upload it to the root directory of your domain. It should display as follows: To do this, you need access to your hosting account. Usually, you can upload a file via your Cpanel hosting management system by using the file manager. This might require some technical knowledge, but it's very simple. If you can't figure out how to do it yourself, be sure to contact your hosting provider for support. If you own a WordPress website, we have created a free plugin you can use to create your ads.txt file. We provide the details in the blog post.

How do I set up an ads.txt file for WordPress?

Download and install the MonetizeMore ads.txt WordPress plugin. It’s free and allows you to edit and create your ads.txt file in the backend of your WordPress website.

How do I fix an ads.txt file?

Download the original file, make adjustments by adding the correct details to the file. Remember, you need to list the network partners/resellers, your Publisher account ID, account relationship (direct or reseller), and the certification account ID. Once you updated and fixed the file, save it, and upload the fixed file to your website.

How do I check my app-ads.txt

Settings might differ depending on the network partner you work with. However, similar to ads.txt, with app-ads.txt you need to upload the file to your developer website. If you’ve already done that, visit

Recommended Reading


What is ad mediation?

Read More

Optimize Page RPMs with our PubGuru Page Report

Read More
Ad Optimization

AdOps Recession 2022: A Wild Ride Ahead

Read More

Enjoying this post? Let's put things to action

Get started