Is roaming free in France with my US or UK SIM?

No, not typically. While EU citizens benefit from 'Roam Like at Home' within the EU, this policy does not extend to non-EU SIM cards. US carriers like T-Mobile or UK carriers such as Vodafone UK will usually charge significant daily fees or high per-MB rates for data usage in France. WestESIM offers a far more economical and transparent solution, providing a dedicated high-speed data plan for France without the risk of unexpected roaming charges, ensuring predictable costs and premium service.