Deposits in Advance
For many businesses, it is common to require a deposit in order to secure a customers booking. For event businesses in particular, this can occur months or even a year or so in advance.
If you export to an accounting suite or report your income tax on an accrual basis, then you will need to create a separate Invoice for the deposit. Both scenarios work on the assumption that an invoice is an invoice, and will not be altered once reported on. Any changes after an invoice is issued should be corrected with another invoice or credit note so as not to effect previous tax reporting periods.
This problem is resolved by creating a separate invoice for the deposit only.
The original booking should remain in "Booking" mode until all goods and services are finalised just prior to the booking event, e.g. 2 weeks before event. At this point, the "Booking" should be converted to an "Invoice", and your customer makes their final payment before the event.