Total VAT Amount needs to paid along with 1st Installment of supplier Invoice

Dear All

There is statutory requirement in Saudi Arabia where, the VAT paid to the supplier needs to fully paid along with the 1st installment of the invoice.

For E.g.

Base Amount - 10000

Tax Amount - 1500

Total Invoice Amount = 11500

If the payment term is 90% and 10% the system splits and creates installment as

10350 i.e. 90% of 11500 and

1150 i.e. 10% of 11500.

Business Requirement

The installment needs to be split as below

90% = 9000 (90% of 10000 Base Amount) + 1500(Tax Amount) = 10500

10% = 1000 (10% of 10000 Base Amount)

We tried to tweak the payment term percentage to derive these values but the 2nd installment of 10% does not match 10% of invoice base amount.