Hello. Sorry if this is very very easy:
I'm using mobile broadband, using dongle K3570-Z (if it makes any difference). My first internet month finishes on October 2nd, assuming that I don't use all the available bandwidth. I've bought a topup voucher from a Vodaphone shop. Can I wait until October 3rd to top up, before using the voucher on my dongle (offline), or do I need to be online (i.e. on October 1st or 2nd) in order for the topup to work?
Cole