How Long is a Smog Certificate Good For in California?
(And Why You Shouldn’t Wait to Use It)
When you pass a smog check in California, you don’t get a forever pass — you get a smog certificate with a ticking clock on it. Here’s exactly how long it lasts, when you might need another test, and why acting quickly is the smartest move.
Smog Certificate Expiration
In California, a smog certificate is valid for 90 days from the date of issuance. This time limit is set by the California Bureau of Automotive Repair (BAR), and it applies whether your test was for:
Registration renewal
Change of ownership (sale of the vehicle)
Out-of-state vehicle registration in California
If you don’t complete your transaction within those 90 days — whether that’s registering, renewing, or transferring title — the certificate will expire and you’ll need to test again.
Why Acting Quickly Matters
Avoid paying twice – If your certificate expires, there’s no grace period. You’ll need to pay for and take another smog test.
Prevent delays – DMVs and private registration services won’t process your paperwork without a valid certificate.
Stay compliant – Driving without completing required registration steps could lead to late fees or penalties.
When You Might Need to Retest Sooner
Even with a valid certificate, some situations require a retest before the 90-day period is over:
Title transfer delay – Paperwork gets kicked back or corrected after the expiration date.
Registration lapse – Letting your tags expire can trigger another smog requirement.