How to handle venue rental deposits?

Commerce7 allows for the creation of general merchandise products that can be used to capture the deposits.

Before proceeding, it may be worth considering handling these transactions outside of Commerce7. It is possible to create a product to charge for the deposit, and a product for the full rental charge, however, this will influence your customer data/reporting and SKU, lifetime value, etc. You may want to consider processing these payments directly through your payment gateway and creating invoices and managing these transactions outside of Commerce7.
However, if the goal is to process the deposit for the rental and the rental fee through Commerce7 under the customer profile, you should create a new product for the deposit and rental fee and create a rebate product for the deposit.
Start by navigating to Store > Products > Add a new product > select the type of product you want to create. General merchandise is recommended. Make sure to select the appropriate tax type.
 
You can follow our documentation on How to Create a General Merchandise Product to create the deposit and full rental fee.
 
Then you can follow our documentation on How Do I Add A Rebate Product? to create a rebate for the amount of the deposit that you can then apply to the order when charging for the full rental fee.
 
Once you have all the products created, when you are processing payment for the deposit you can use the deposit SKU.
Then when processing for the full rental fee, select the rental fee SKU and then apply the rebate deposit SKU to "apply the deposit" and then they will only be charged for the remainder.