Invalid traffic & fraud · also called TAG CAF, Certified Against Fraud seal
TAG Certified Against Fraud
TAG Certified Against Fraud is a certification from the Trustworthy Accountability Group for companies that meet anti-fraud requirements such as MRC-standard IVT filtering and supply-chain transparency.
TAG was created by US advertising trade groups to fight criminal activity in digital advertising. Its Certified Against Fraud programme gives companies, from advertisers and agencies to ad tech platforms and publishers, a seal showing they follow a set of anti-fraud practices.
Requirements vary by company type but centre on filtering GIVT and SIVT in line with MRC standards (often using accredited vendors), implementing and honouring ads.txt, app-ads.txt and sellers.json, using TAG data-center IP lists, having a named compliance officer, and completing training. Companies can self-attest or be independently validated.
The seal matters because buyers can prefer paths where every participant is certified, known as a TAG Certified Channel. TAG has published studies reporting considerably lower fraud rates in such channels than in the broader market. Certification is not a guarantee that a company never carries fraud; it indicates that recognised processes are in place and audited or attested.
Think of it like this
It is like a food supplier's safety certificate: it does not promise nothing will ever go wrong, but it shows the kitchen follows inspected hygiene rules.
An example
A European brand instructs its agency to buy only through DSPs, SSPs and publishers holding the TAG Certified Against Fraud seal, removing roughly a third of its previous supply paths.
Related terms
TAG (Trustworthy Accountability Group)
TAG (Trustworthy Accountability Group) is an advertising industry initiative, founded in 2014 by the ANA, 4A's and IAB, that runs certification programs against ad fraud, malware, piracy and for brand safety.
TAG Certified Channel
A TAG Certified Channel is an ad supply path in which the buyer, the seller and every intermediary that handles the transaction are certified under TAG's Certified Against Fraud program.
MRC IVT guidelines
The MRC IVT guidelines are the Media Rating Council's standards for detecting and filtering invalid traffic in ad measurement, defining the GIVT and SIVT categories that accredited measurers must handle.
ads.txt
ads.txt (Authorized Digital Sellers) is a public text file on a website's domain listing which ad sellers and accounts are authorised to sell that website's ad inventory.
sellers.json
sellers.json is a public file in which SSPs and exchanges list their seller accounts, naming who owns each one and whether it is a publisher or an intermediary.
Sources: TAG Certified Against Fraud program, Trustworthy Accountability Group (TAG)