Obviously, it's better (cheaper) to leave the money in your savings account until it's time to pay the balance.
But you can pay as often as you wish by calling WDTC-UK
It's not cost effective though, since you don't get the interests from your savings account.
One reason to do monthly payment would be to make sure you can pay off. Some people just can't keep money in their account, and will spend it no matter what, so they'll find it easier to pay monthly rather than take the risk to spend that money on other things.
Another reason would be if your CC (Debit card actually) has a low payment limit.
My gold Mastercard used to have a £3000ish payment limit over 30 days, which was too low to be able to pay for my balance.
Strangely enough, my bank was willing to temporarily raise that limit for a fee ... £20+ for one month ...

but they could also permanently raise that limite for free ...

now I've got a £7000 limit over 30 days, so that's ok, but if I had not managed to get that, I would have needed to pay in installments.
If you have a savings account, and if you can pay in one go, then wait until your deadline.
Let your money work for you and earn you interests, the mouse already makes enough dough
