MBNA let you write credit card cheques so I guess they could be lodged in a deposit account.
It would be totally insane to do that though. They'll of course start charging interest straight away as it is a cash advance. Whatever way you get the money they'll treat it as a cash advance.
Does the regular saver T&Cs let you reduce the payment or take a break on making payments?
They're not going to let you buy financial products (deposits in this case) with a credit card on free credit. Everyone would be doing it if you could. This is very different from paying a normal bill for a product or non-financial service.
I don't know if the OP is asking the question because:
(a) they have run out of cash and can't continue a regular savings plan thereby losing out on the higher rate of interest and want to fund through credit (a bad idea IMHO); or
(b) they want to take advantage of an interest free period (e.g. first 6 months) and fund the savings plan in that way (a good idea, but probably a non-runner).
If you were looking to invest by taking advantage of the interest free period on purchases offered by some credit cards - one way is to buy Prize Bonds. They can be bought with a credit card. Buy them on a new interest free credit card - cash them in a few weeks before the interest free period ends - and any prize money you get is a non taxed money for free. Risk free. You have to make the minimum repayment on the credit card each month (usually 3%).
Not a mainstream investment idea - but worth a go ?
If you were looking to invest by taking advantage of the interest free period on purchases offered by some credit cards - one way is to buy Prize Bonds.
That's an idea I toyed with myself while trying to think of ways to turn the interest free period into cold hard cash but I don't think the prize bonds T&Cs allow it.
You have to hold the prize bonds for at least 3 months before cashing them in. Prize bond FAQ .
Although if you moved the balance to another credit card with an introductory interest free period it should work.
That is what I meant - take out a new card with the 6 or 9 months interest free credit offer - then buy the prize bonds and cash them in just before the offer period ends - I wasn't trying to say that you buy them at the start of the month and cas them in before the end of the month.