If you go to www.nc.gov and click on the vehicle inspection link over to the left, it tells you all about it. You can get your vehicle inspected up to 90 days prior to the date your registration expires and you have to get it inspected by the last day of the month in which the registration expires, or they will block your registration and charge you fifty dollars to unblock it. You do not have to get your vehicle inspected more than once in 12 months. If the inspection is due now, then go ahead and get it, and the inspection will expire 12 months from now plus the time it takes to get back to your registration expiration date. So, inspection due now, and tags in say, 4 months? Your inspection will last you sixteen months. They recognize that it will take over a year to get everyone in line. There are so many people who never get inspected and they say this should increase compliance. In other words, the fine is greater for dead plates and registration because you did not get inspected than it is for just not getting inspected.