I have not used www.callineurope.com , but have seen the website. You are much better off buying a sim card in the UK. If you look at the T&C I think they have a $65.00 a year fee to keep active. I have had a vodaphone card for several years all I have to do is send a sms every 180 days to keep active. If you roam on the call in europe card it is expensive. I uderstand that the data charges are crazy something like $5.00 a mb. Local sim cards have a cap on roaming set by the EU. I hope this helps.