Forbes estimated Guillaume Pousaz's net worth at $7.8 billion in May 2025. His wealth comes almost entirely from Checkout.com, where he is CEO and is reported to own about two thirds of the company.
The figure has moved with the company's valuation. After the January 2021 fundraising, Forbes put him at about $9 billion in an April 2021 article. In January 2022 Checkout.com raised $1 billion at a $40 billion valuation, and The Guardian estimated his stake at about $20 billion.
The Sunday Times Rich List 2022, published on 20 May 2022, ranked him fifth in the UK with an estimated 19.259 billion pounds.
The gap since then follows the company's value. Checkout.com was marked down internally from $40 billion to $11 billion in 2022, and a September 2025 employee buyback valued it at $12 billion. The company was profitable in 2024.