When receiving large payments it is not practical to process them in one seating. I realized since we do it for usually for business partners and documents like invoices when implementing SAP business one setup why not try it in production with an incoming payment It is simple the only two items really required are the found in the templates folder for data migration under the incoming payment folder.
First the header details are required such as the amount paid.Which will be filled under the column of the method of payment and the account the payment is to be received. This is the template OCRT.
Second the line items in the RCT2 templat. This is usually straight forward in most cases it is the docentry of a document which is not the same as docnum. It could be found when making a query such as SELECT DOCENTRY FROM OINV WHERE DOCNUM = X. Then the sum applied is required. In most cases that is it. There are exceptions.
Of course the first column in the excel template have to match with the same number which SAP will override and assign its own number when posting the payment.
Once ran SAP will do all the calculation and spit out processed payment. There are times when more details are needed such as whether a document is an invoice. Fill in anything that may make it easier the software to determine what it may be.