Just bought yourself an iPad 2? Want to use it abroad this Easter? You might be shocked by how much it could cost. We’ve discovered that data roaming can be 1,000 times more than equivalent internet use in the UK!

I recently got an email from a Which? member, Mark Jones. Mark planned to buy an iPad 2, due for release a few days after he emailed us, but he had questions about using it abroad:

‘I’ve never written to you in such detail before, but I feel compelled to tell you about this in detail. I travel to Turkey regularly so I am interested in the international roaming charges for data on iPad plans. I am disgusted with the findings of my research,’ he said.

When I followed up on Mark’s concerns – which focused mainly around operators’ lack of transparency and misleading information relating to iPad roaming costs – I soon understood why he felt the need to get in touch.

My colleague Catherine West kicked things off by trying to uncover tablet data roaming charges on company websites. In some cases she found that there wasn’t any information about this on tablet tariff pages. International charges were often only covered in a general price guide elsewhere on the site, meaning it’s left to us to guess whether data roaming charges for mobile phones also apply to tablets.

Up to 1,000 times more expensive

But transparency isn’t the only worry for iPad-using globetrotters. Within the UK, on a Sim-only tablet plan, one gigabyte (GB) of data typically costs between £7.50 and £15 a month. We discovered that data roaming can cost hundreds, even up to a thousand times, more than this equivalent UK use.

Tablet operators usually charge for international use on a per megabyte (MB) basis (there are 1,024MB in a GB) so it’s not easy to directly compare costs. And some operators have protections in place to minimise your risk of running up astronomical bills (such as 3’s £50 monthly bill cut-off). But let’s say they didn’t, and left you free to use a GB of data overseas – by watching a few hours of online TV, say.

This is how much I calculated that the UK’s five mobile networks would charge to use a GB of 3G tablet data in the USA. You might want to sit down for this:

Orange – £8,192 (it only allows data roaming on Samsung Galaxy Tab plans)

T-Mobile – £7,680

3 – £3,072 (but pop over the border to Canada and that’ll be more than £10,000 please)

Vodafone – £600 (charged in usage blocks at a rate of £29.99 per 50MB per day)

O2’s tablet plans don’t allow data roaming – maybe that’s a good thing?

Up to £10,000 for a GB of web data? I thought I’d got my sums wrong. But careful checks by Catherine confirmed my calculations.

Data roaming charges beggars belief

Mark says he’s a proponent of the ‘caveat emptor’ rule – read the small print before signing up to any contract. If he can see the charges, he says, then it’s his responsibility to use the service within its limits.

That’s a very reasoned and rational approach – assuming that the transparency is there in the first place. But I’m occasionally inclined to be not-quite-so-reasonable about such matters.

And I reckon the sheer scale of these data roaming charges are frankly ridiculous for a device that was designed with ultra-portability in mind. Who’s with me?