If you are renting out highly valuable products it's advisable to add a security deposit for every booking happening. You have to use our deposite item type. The deposit item type has 0% tax rate by default and shows the deposit outside of the tax relevant cart and invoice total amount, because it is no tax and invoice relevant thing.
Setup
1 )To add a deposit automatically to each booking create a new one first via the creation menu:
2) Then describe the deposit like any other and set the price to per item to only add it once and not based on time. Tax rate has to be 0%.
3) Lastly navigate to the availability settings of your deposit article and add the products you wish to add the deposit automatically to, once a rental is added to cart.
Once you created a deposit, it can be used for all products by adding individual articles or groups to the list.