Holidaymakers heading outside the EU have been warned of potentially high mobile phone charges, with some providers charging up to £8 per day for minimal data usage. To mitigate costs, financial expert Martin Lewis suggests using international eSims, which offer benefits similar to traditional sim cards without the high fees. Lewis shared his positive experience using a 10GB eSim for £18 during travels outside Europe, contrasting it with his provider’s £6 daily charge for a 500MB limit. eSims allow travelers to connect to foreign providers with a separate data allowance and are easy to set up. Before purchasing, travelers should check their phone’s compatibility with eSims.