Hi @amin.shatat ,

There is option to update the retention amount in Purchase order & this amount will create as different installment in the final invoice once user match with purchase order.

1. RMB on PO & select payment schedule.
2. select the pay schedule line type as ‘Retention’, retention % or amount and due date. Refer below screen preview for easier reference.
3. Then follow the normal GRN procedure and match the PO with invocie
4. Then it will create 2 installment for same invoice. (different installment for retained mount with due date mentioned in PO.)
5. User cannot authorize that installment for payment until PO retention line approved by respective user

Hope this information would be useful.

Best Regards

Narmada