Question: if I buy a SIM for my mi-fi unit and that SIM comes with a 30-day bundle, when does that 30 day period start? Is it the first time the SIM registers with the SP, or is it the first time a data transaction takes place? I have several such SIMs but haven't used any yet. I suppose it could be that the first time I go on line I have to give ersonal info so as such that could/would be the start of the 30 days - or is it? For info Sainsburys are currently doing EE SIMs with a 200MB 4G 30-day bundle for £1 - not bad for e-mail only?