eSIMs (digital SIM cards activated by QR code or app) work without physical SIM swap and offer significantly cheaper data than international roaming. Worth setting up before travel for most international trips.
Best UK-friendly eSIM providers
Airalo (most countries, easy app). Holafly (unlimited data plans). Nomad (good Europe coverage). All work alongside your main UK number — you keep WhatsApp, calls in airplane mode, data via eSIM.
When eSIMs particularly help
Long trips where roaming costs accumulate. Multiple countries in one trip. Remote work locations needing reliable data. Backup connectivity for emergency.
Set up before departure. Most providers activate in minutes via QR code. Test before leaving home. Significantly cheaper than EU roaming (post-Brexit) or rest-of-world roaming.