Customers in Britain ate five million in total over 2015, while vegetarian sales showed double digit growth, according to the annual report.
Coffee was still a strong staple for Pret though, with branches selling 1.5 million cups a week globally.
Overall sales came to £676 million ($967 million), including a 7.5% growth in like-for-like sales which did not account for 36 new stores which opened worldwide.
The chain reports having 399 outlets globally at the end of 2015. In the US it had 65, a market which saw a strong 13.8% growth in like-for-like sales.
Noting the UK's appetite for vegetarian cuisine, Pret A Manger's CEO Clive Schlee said the company had benefited from catering to a growing demand:
"Last year thousands of customers told us they were trying to eat less meat. This year we have challenged ourselves to increase our vegetarian options in all shops, as well as opening a veggie-only pop-up shop to learn more from our customers.
"We will of course still focus on the essentials: engagement of our wonderful team members, the freshness and quality of our ingredients, and securing top class locations around the world. This gives us confidence for the year ahead."
Pret A Manger is owned by private equity investor group Bridgepoint Capital. Last year Bridgepoint said it had no plans to float the chain on the stock market, according to City AM.