CMP (Consent Management Platform)
A CMP is the tool that displays a website’s or app’s cookie notice, records what the user accepts or rejects and passes that choice on to everyone involved in serving ads.
It is what sits behind the notice that appears on almost every European website. As well as showing it, the CMP stores the user’s choice, honours it on later visits and communicates it to advertising vendors, nearly always through IAB Europe’s Transparency & Consent Framework (TCF), which turns consent into a text string that DSPs, SSPs and measurement providers can read.
Since 2024 Google has required publishers that monetise European traffic with its tools to use a TCF-certified CMP, and in Spain the data protection authority (AEPD) requires rejecting to be as easy as accepting. The CMP largely determines how many users can be reached with personal data: a confusing or poorly designed notice lowers consent and, with it, the reach of data-driven campaigns.
