The music streaming service offers a free version supported by ads, and a Premium version – which is £9.99/month in the UK – which allows users to listen ad-free and download music to listen to offline.
However 2 million users have managed to access an ad-free service by using unauthorised ad-blocking apps.
Spotify revealed the findings as part of their risk assessment, ahead of their public offering on April 3.
“On March 21, 2018, we detected instances of approximately two million users as of December 31, 2017, who have been suppressing advertisements without payment,” the company said on Friday (March 23).
Read more at NME