Negative number on payment

Hello is there a way to authorize negative number went making a payment?

This is the reason why
In my country we have to retain 1% for local sales tax to every payment made over 1,000.

I need to input payment like this

Supplier    1000.00
Local Gob. Tax -1.00

this is what it should be

                                  debit        credit
Supplier                  1,000.00
Local Gob. Tax                               1.00
BANK                                         999.00

Thanks