Yesim

Yesim was founded in Switzerland in June 2019 and has grown from a few hundred thousand customers in 2024 to a claimed network connecting more than three million travelers through partnerships with over 800 carriers worldwide. The core product looks like most competitors, fixed data packages of 3 to 30GB over 7 to 30 days, but its Pay & Fly plan stands apart: instead of picking a bundle size in advance, you buy one plan that works across more than 100 countries and pay only for the data you actually use, at a fixed per-gigabyte rate.

That pay-per-use structure suits people whose itinerary isn't locked down, since you're not stuck estimating data needs for a trip that might change. Yesim also offers a separate unlimited option for people who know they'll be streaming or hotspotting heavily, priced higher than the standard packages. Everything here is data-only, and top-ups happen inside the app without needing to buy a fresh eSIM. It's a reasonable pick for anyone who wants European support hours and a company with a clear public track record rather than an anonymous reseller shopfront.