How do I do a smog check lookup for a used car?
Where to look and what you will need
In states that run smog or emissions programs, the testing agency or motor vehicle agency keeps records of inspections. Many let you check online with the license plate number or the vehicle identification number, a 17-character code found on the dashboard near the windshield and on the driver's door jamb. Some require only the VIN, so have both ready.
Results usually show whether the car passed, the test date and the type of station. If there is no record, that may mean the car has never been tested in your state, or that it is exempt because of its age or model year.
- Vehicle identification number from the dashboard or door jamb
- License plate number and state
- Seller's name or address for context on prior registration
- Paper test certificate if the seller has one
- The official state environmental or motor vehicle agency website
Why this matters for a used car
A current passing test can help you confirm the car is legal to register in that state and that its emissions equipment is working. A failed or missing record can lead to repair costs before you can register the car. Check the rule for your area, since some vehicles are exempt and some areas have no testing at all.
Ask the seller for the most recent certificate too. An online lookup may lag a few days behind a new test, so a paper copy can help if the record is not updated yet.
Common mistakes
- Assuming a passing test means the car has no other mechanical problems.
- Entering the wrong VIN digits or plate number and trusting a no-record result.
- Paying for an emissions repair before confirming the car actually needs one.
