if our clients do not pay our suppliers with the amount arranged on the due date we lose a percentage of our discount. Are we allowed to debit our clients with the percentage we lost?

The transaction between yourselves and your suppliers is different from that of yourselves and your clients. They are two different transactions. You cannot debit your clients for the settlement discount you lost out from your suppliers.

As an alternative, you make timeous payments to your suppliers directly and qualify for the discount. You may also raise the price of the items and offer a discount to the clients who make timeous payments. However, the discount will only be a moral issue and not binding on yourselves.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai