I have a few SIM cards that I want to keep active, but don't use for anything other than receiving verification codes.
These require regular topups to keep them alive, and all vendors have a minimum top amount. Any know any hacks to avoid this?
Also - anyone know how long a sim takes to expire - is it 1 year with no topups across the board?
Once you start using a SIM then generally a year is about how long you get for it to remain active without a topup.
I would suggest you just get a new SIM rather than trying to keep it going as you will spend more on the top-up than the cost of a new SIM card.
Frequently you can get these on special - currently Noels have One NZ and Skinny for $1.(noelleeming.co.nz) and PB Tech have One, 2Deg, Skinny, Spark(noelleeming.co.nz) for the same price.