According to the Massachusetts' Driver's Manual once you have established residence in Massachusetts, you must obtain a MA driver's license to retain your driving privileges, there is no grace period. The same is also said for registering your vehicle, again no grace period once you have established residency. Having a Massachusetts bank account or a utility bill is enough to show MA residency.

So it would appear if your son's girlfriend has started up a bank account and is planning on being a resident of MA she needs to obtain a Massachusetts driver's license immediately and also register her car in this state without delay.

The MA Registry of Motor Vehicles (RMV) gives detailed information on how to convert an out of state license, so her California license, to a Massachusetts driver’s license. This includes fees, testing requirements, etc. The RMV also gives more information on how they process out of state conversions for a vehicle, the forms, fees, etc that must be filled out and paid to transfer a car’s title and registration from CA to MA.

To convert California registration to Massachusetts registration there are several steps that the Registry of Motor Vehicles lists on its site. One is that the car owner must go to a licensed Massachusetts insurance agent to obtain an active insurance policy and have the agent complete, stamp and sign an Application for Registration and Title (RMV-1).

Your son's girlfriend can get instant car insurance quotes online here with us so that she can obtain a MA policy on her car and register it properly in Massachusetts.