I sometimes travel to the US (two or three times a year) and a couple of weeks back bought a 30 day data SIM for my iPad and a 30 day voice SIM for my phone. I still have data and minutes, but won't be back 'til Sept - what is the least expensive way to extend these chips 'til I return - so I don't lose everything? I think I will need to add a bit over each 30 day period or something over the Internet ...
Thanks in advance!
Ex-pat Liz