ABC are still on the old system (as far as i know) so SHOULD be able to backdate it to the date on the letter that will be sent to them... i wn't guarantee anything but from what i understand they should still be on the old system

the new system, when the centre submits their usage each week, they get notified of percentage there and then, so if it hadn't been processed at c'links end when they put in the first usage statement, it might not show up. definitely take the letter in