Partial payment in SAP is a payment that is posted to an account without any open items being cleared. Allocation of this partial payment to an open item is to be carried out. When posting, the system marks the document number of the original open item in the line item for the partial payment.
The original open item and the partial payment remain open. The system stores the document number, fiscal year and number of the line item from the invoice in the partial payment. This information can be found in the Payment for field.
Thus it is possible to refer to the original open item from the partial payment in SAP. When posting for the remaining amount of the invoice, both the partial payment and the invoice are to be manually cleared. However the disadvantage in this system is that the system would allow payments in excess of the open item and no control is possible in SAP.
Residual item in SAP results when a payment is made for less than the actual amount outstanding. The original open item is cleared and the system posts a new open item. This new open item is for the same amount as the original open item minus the amount paid.
When the document is posted, the system stores the document number, fiscal year and item number of the original open item in SAP. For the residual item, SAP either uses the terms of payment from the original invoice item or enters the predefined terms of payment. Which payment terms are used depends on the settings made for the tolerance group in the vendor master data. The disadvantage is that the original document number is lost as the system assigns a new document number.
For payment differences, system always looks for two types of tolerance in SAP: 1) Tolerance group for employees 2) tolerance group for vendor/customer. So this customization has to be remembered before any posting to GL Accounts.
If the payment difference is within the limit, a cash discount will be posted automatically and the payment difference will be either treated as an additional cash discount or charged to an expenses account.
If the payment difference is outside of the tolerance limit, the payment will be processed as a partial payment, a residual payment, or a payment on account. You can also process the payment difference manually.
In case of partial payment, all line items will remain as open items. With a residual payment, the system will clear an invoice with payment and create a new open item for the differential amount.