I have a 500mb sim in my ipad mini for when wi-fi is not available or for emergencies. This costs £10 per month with no roll over of unused data allowance. There are now several other providers who have some kind of roll over but not BT.
Wouldn't it be great if BT allowed roll over of data? This would be better value for money and it would mean that an allowance could be built up over periods of little or no use to be used when needed on holiday etc.
Also, has anyone manged to make use of the wi-fi hot spots that BT says we have access to whilst aboad?