No it's not instant. Usually you need to do a Bpay at least the...

No it's not instant. Usually you need to do a Bpay at least the day before to be fairly sure it is going to get there on time because BPAY bank transfers are not cleared in real time. However, when the funds are received, the effective date of drawing of funds is the date when you sent them if sent before end of business. Whether MST will accept funds coming in late but dated on Monday is up to them. I'd expect they would be lenient if it is legally possible for them to do so as they want the money.