Recurring Sub concern

[Enkidoh]

Well, when you sign up your card, SE 'tests' it, by making a small ($1) 'authorization fee' which after a week is refunded back to you by your card issuer. Hence if the authorization fee doesn't go through right away, SE knows your card will be invalid and hence the Mogstation would have informed you of it immediately (as a lot of players have found out the hard way).

Really, as long as your debit card account has enough funds to cover your FFXIV fees on the billing date (SE will email you five days before the date the card is billed, thus giving you time to ensure you have the funds to pay it), you should have nothing to worry about (I pay through a Visa debit card myself for my FFXIV fees so I have a little experience in it).