Reporting pre-payments made for next year

Q. How can I get a report of all pre-payments made in 2018 for 2019 reservations?

A. Here's what I would suggest to get the pre-payments made for the prior period:

Start with the Receipts by Payment Method quick-report (Reports / Transactions, click Receipts by Payment Method).

Go to More Filters to get to the Transactions Filter, then click on the Sites/Reservations button in the lower right, check "Filter by Date" and select "Start Date", and put the desired reservation dates (e.g. 1/1/2019 to 12/31/2019).  Click OK to get back to the Transactions Filter.

In the Transactions Filter, uncheck all 6 of the "balance" boxes underneath the Sites/Reservations button (to exclude any non-reservation transactions like Customer or Unbound).

Click OK on Transactions Filter.

Optionally, click on Summary Options, and change the Summarize period e.g. to Monthly, and click OK (don't click the quick-report again, that will clear the filters).

Finally, select the From and To dates of the transactions to report to bet the Transaction date range (not the Reservation dates)  -- e.g. 1/1/2018 to 12/31/2018.

Now you should be showing the total payments made in 2018 for 2019 reservations.  If you want the details of course you can uncheck Summarize.

Note: This can only be done with the Receipts by Payments report, not with Receipts by Category, due to the filters needed.