is there any way to add a percentage field calculated on total invoice/quote amount (named agency fees as an example) and linked to specific account
example:
Subtotal: 1000 (posted to account i choose)
Agency fees 5%: 50 (posted to specific account) (The ratio is not fixed)
Total: 1050 (posted to account receivables)
i tried the custom tax code but the posting was not as i wanted