GiffGaff

GiffGaff is a UK-based MVNO on O2's network offering eSIM with no tethering restrictions or throttling. Every data plan includes full-speed hotspot capability, so turning on personal hotspot doesn't trigger hidden slowdowns or require expensive add-ons. Their pay-as-you-go model lets you buy data bundles without committing to monthly contracts, making it flexible for occasional travelers.

GiffGaff works well if you're based in the UK or frequently visit and want budget pricing without surprises. The transparent rate structure shows exactly what you'll pay, and the community-driven support forum is active and helpful. Outside the UK, it's less practical since roaming charges apply, unless you're traveling within Europe where rates are competitive.