To change the allocation the bill will need to be reversed.
This can be done by the below:
Go into General Postings from the main menu.
Select SIB and then tick the box for reversals.
Click on NEW.
Put in the Matter number and then select the bill in the allocation box.
Select the Floppy disk button to save once the information is populated.
Select POST.
N.B
If the bill has any allocations like money received against it TCO/TOC/BRO or credit notes SCN then these will have to be reversed first by using the same method as above but selecting the original transaction type.