Well they specifically said "renewal" so the business just wouldn't renew them and therefore not cost them any more money.

Obviously some services like insurance or storage don't work like this, though. I don't want to use them, but I want them to be there if I do need them.

Could you just give the option for them to delete the account if they want to at the same time? I assume most wouldn’t want to, but if it costs them money to keep inactive accounts then they can choose to. Out of interest what sort of services were you thinking of there?