How can a BACS payment reduce funds immediately?

GemmaD27

I have always been taught that a BACS payment (which takes 3 working days for the supplier to receive payment) does not reduce the banks funds immediately. I've just done a practice test on the AAT website and got a question wrong because I put a BACS payment 'would reduce funds at a later date' but the answer is actually 'reduces funds immediately'. Why is this?

davealucas

Until a few years ago, a BACS payment would leave your bank immeadiately, but would take three days to be processed before appearing in the suppliers account.

More recently, banks have a process called "faster payments" (which is still a form of BACS payment) where the transaction can take place in a matter of a couple of hours!