Orders intended to be paid offline are collected in the Billing Director - Receivable - Documents - Orders list.
You can enter an offline payment from the Billing Director - Receivable - Documents - Payments. When you enter a payment, you will be automatically offered to apply this payment to the unpaid order ( or invoice or debit adjustment, if such exist for a given account)
In some cases to fasten the Order payment process (or if you have an arrangement with the Account holder), you can select the payment method and pay an Order online or apply existing payments. To this effect select an order and click the Details tab. Then click the Change Payment Method button. The list of all payment methods available appears on the screen. You can pay by the credit card (use the existing one if any or enter a new one), a bank account or you can pay offline using both the new offline payment or credit adjustment or the existing ones.