I found this information in KBA 2692119 regarding prepayments:
9. How are payments before the contract start handled?
You have a contract with a due date in advance. In addition, the due date is moved forward by x days. For example, the payments for a monthly rent are made on January 22. December of the previous year.
If this contract has not yet started, SAP will:
The RoU and the leasing liability linked to the RoU are posted at the valuation start date (usually contract start date)
No interest is calculated for the period before the contract start date.
The payment made for the first rent (x.day of the previous period) is now displayed as a balance on the clearing account (as deferral item) up to the creation of the leasing liability.
Currently I cannot obtain the deferral item on the clearing account for the first rent. So, is it possible to work with prepayments in the contract? If so, what are the steps to take regarding configuration and contract master data?