How much data do you actually need?
For a one-week trip on maps and social media, 3 GB is plenty. For two weeks of video calls and streaming, plan for 10 GB. Built-in 'unlimited' plans usually throttle after the first 5–10 GB; the named-quota plans are honest.
Does the provider use real local carriers?
Some travel eSIMs roam on whichever network has the cheapest agreement, which means slow speeds. Simline plans are listed with their underlying carrier — Airtel India, KDDI Japan, Vodafone UK — so what you see is what you get.
How honest is the pricing?
Watch for daily caps, hidden activation fees, or 'starting from' rates that don't reflect the plan you actually need. Transparent providers show the total upfront in your currency.
Refund policy
If you can't connect within 24 hours, you should get a refund — full stop. Plans that void refunds the moment they're 'delivered' are a red flag.
Support
In-app chat that responds within an hour beats a generic ticket queue every time. Test the support before you fly.