Yes, it could be possible to charge more than the security deposit if closeout charges related to the rental exceed that amount.
For example if the security deposit is $1,000 and a renter uses more mileage than originally set in the booking, totaling $1,200, then the renter will have to pay the additional $200 to cover the mileage charge.

One the other hand, in case of damages, or if the RV is not insured through RVezy, the maximum amount that can be charged to the renter is the security deposit.

As part of the checklist, make sure to take all the necessary photos when collecting and returning the RV to document well the state of the RV to avoid disagreement in regards to additional charges.