"To finalize the paperwork" means to complete and finish all the necessary documents or forms that are required for a particular task or process. Full definition
Heck, you can't even finalize the paperwork in most states until the dealership has your proof of insurance. (policygenius.com)
The dealership was also open later hours, which was nice since we live outside of town and had to drive back in to pick the vehicle up after finalizing the paperwork. (autolist.com)
Once done with Michael and Al we went back to Joe to finalize the paperwork for the leases. (dealerrater.com)