How soon after someone moves from interstate should the car registration be changed?

Question

The cars are registered in NSW but they have been living in Canberra for just over a year

Answer 1

Registration needs to be done within 30days.

Answer 2

I think I understand your question. You are asking that when a person moves, or buys a car registered in one state, and then moves the car to another state, should the registration be changed?

If that's correct, then first of all you now driving a vehicle with out of state plates because you cannot change plates from one state to another without also registering it in that state you are driving it.

If you are simply visiting for a few months then most likely you are fine as long as your address is still valid in the state where the car is registered. Otherwise, you will now be a target for police and CHP who monitor out of state plates. Once you are pulled over whether you get a ticket or not, your vehicle is now on record as being driven in another state, and you will soon be receiving a notice from the DMV and perhaps with penalties.

Also, your insurance company may not offer insurance coverage in the state you are driving, so you could be at risk. If you are now a permanent resident and your insurance company finds out, you could be dropped, and they too could notify the DMV. Either way, if you have moved or you will be living in the other state for longer than 6 months, you had better register the vehicle in the new state and move your insurance.

Note, that you will also be paying sales tax, and your vehicle will most likely be required to pass smog as some states have different rules. All of this is most likely why you asked the question as this can be expensive, but it will be more costly if you are fined.