Will my UK or US SIM provide free roaming in Portugal for my adventure?

For most adventure travelers from the UK or US, relying on your home SIM for free roaming in Portugal isn't a safe bet. While Portugal is in the EU, the 'Roam Like at Home' benefit primarily applies to EU citizens. For UK travelers post-Brexit, many major carriers like Vodafone UK or O2 have reintroduced daily roaming charges, which can quickly add up on a multi-day trek. US carriers such as AT&T, Verizon, and T-Mobile typically offer expensive international day passes or per-MB rates. An eSIMAdventures plan offers predictable, cost-effective data without hidden fees.