Mint supports international coverage in a wide selection of countries. The way it works is you add international roaming credit to your account, which can be purchased in either $5, $10, or $20 increments, and then your international minutes, texts, and data usage will automatically deduct from your international balance on a pay-per-use basis.
The rates for minutes, texts, and data vary from country to country. Here are the rates for a few countries below:
Mint Mobile's international rates for minutes and texts are reasonable, but their rates for data usage are expensive. $200 per GB of data usage in the U.K., for example, is incredibly expensive when you can get 12GB of data per month from Three (a cell phone carrier native to the U.K.) for an equivalent of $25.18 USD.
If you plan to travel abroad, we think you will get a much better value signing up for a cell phone plan local to the country you are visiting, or by activating a data-only eSIM plan from Airalo, US Mobile, or eSIM.net.