You might want to disable the data roaming setting in the "Cellular Data" section of the phone's Settings. It actually defaults to off in my experience, but may

You might want to disable the data roaming setting in the "Cellular Data" section of the phone's Settings. It actually defaults to off in my experience, but maybe some SIM-locked ones have it enabled by the carrier by default? Otherwise, I agree, the typical data roaming charges are ridiculous. I don't see why they should be more than, say, twice your home rate (as there are 2 companies involved). Many of the mobile networks are giant multinationals anyway - the fact that roaming in, say, Vodafone.de's network as a Vodafone.co.uk customer, costs a made-up amount of money is just ridiculous. Hutchison 3G ('3') actually have a system called '3LikeHome' in some countries, which let you roam in foreign '3' networks for the same price as your home network - this only includes calls and texts to other 3 numbers, but also, crucially, data. It's great, but there aren't many countries covered by it. And I can only assume it's not driving enough customers away from other operators to affect their bottom lines. But then most people don't seem to choose their phone tariffs rationally anyway. (OMG! A free phone! Only €50 a month! [NB: minimum contract 2 years]) I'm just fearful that taking the SIM card out of the equation will leave us in a worse position, where we can't even work around the problem by buying prepaid SIM cards when abroad.