You can renew your registration online HERE.
If you are too far expired to renew online, you will have to come in to one of our offices to renew. If your vehicle has been expired for 12 months or less, you will still be renewing for the same calendar months that you were originally registered for. (e.g. If your vehicle was due to renew in July and you come in to renew in December, you will still be due in July the next year.)
If you have been expired for more than 12 months, you will start a whole new registration year, meaning 12 months from the time we process your renewal. However, you will also be charged for new license plates, as we cannot renew plates that have been expired for too long.
You cannot renew your out-of-state registration in Montana.