Transaction BOTPAY is used either to send documents

1) Under an export collection (without settlement), that have been received and checked
2) Or to send and to settle/accept the documents at the same time.

When dealing with sight documents,

The default procedure is set up so that the collection is settled instantly. If the document set is paid in full, this is then closed and the closing date of the contract set at today's date.
If the collection is partially paid, the open amount is reduced by the partial payment amount and the contract remains open until the remaining amount is settled.

When dealing with usance documents, The documents are accepted, the appropriate maturity posted and a temporary settlement generated.

However, this temporary settlement cannot be generated if several usance maturities are posted. In this case, only a final settlement for fees is created.

The final settlement of usance maturities at the due date takes place in transaction “Settle Usance Documents at  Maturity” (BOTSET).

Checking the “Free of Payment” checkbox indicates that the collection is to be settled value-free. The collection is then settled instantly without payment. Detailed information on this option can be found under “Free of Payment”.

Should documents be queried or returned, this is dealt with in “Processing Discrepant Documents” (BOTDCR).