To sell a used catalytic converter in California, you generally need to be the documented owner of the vehicle it came from, bring a title or registration whose VIN matches a VIN permanently marked on the converter, and take it to a licensed core recycler who will pay you by check or card rather than cash. Vehicle Code 10852.5 controls who a recycler is allowed to buy from, and Business and Professions Code 21610 controls how the transaction itself has to be documented and paid. Together they rule out the quick, anonymous scrap-yard sale that used to be routine.
Who Is Allowed to Sell a Converter at All
Vehicle Code 10852.5 makes it illegal for anyone to buy a used catalytic converter unless the seller falls into one of six authorized categories: licensed auto dismantlers, core recyclers with a fixed place of business, licensed motor vehicle dealers and lessor-retailers, licensed automotive repair dealers, other licensed businesses whose normal operations reasonably generate used converters, and individual vehicle owners who can document lawful ownership.1California Legislative Information. California Code Vehicle Code VEH 10852.5
If you’re a private person selling a converter that came off your own car, you fall into that last category. Everything that follows is about what the law requires of you to prove it.
What You Have to Bring as an Individual Seller
A recycler following the law cannot buy from you unless you can show two things. First, a certificate of title or vehicle registration that identifies you as the legal or registered owner of the vehicle the converter was removed from. Second, a VIN permanently marked on the converter that matches the VIN on that title or registration.1California Legislative Information. California Code Vehicle Code VEH 10852.5
“Permanently marked” means engraved, etched, welded, metal stamped, acid marked, or applied by a similarly reliable method to the exterior case of the converter. You’ll also need a valid driver’s license or California-issued ID, because the recycler is required to record its number and state of issue.2California Legislative Information. California Code Business and Professions Code BPC 21610
Plan on signing a statement that you own the converter, and expect to be asked for a copy of the title in some cases.
If Your Converter Doesn’t Have a VIN Engraved on It
This is where private sellers most often get stuck. If there is no VIN on the converter itself, there’s nothing for the recycler to match against your title, and the verification the statute requires cannot be performed.
Under Vehicle Code 24020, added by Senate Bill 55, dealers now have to permanently mark the VIN on the catalytic converter of any new or used vehicle they sell, with limited exceptions for collector vehicles, motorcycles, salvage pool and wholesale auction sales, and vehicles sold by licensed dismantlers after being reported for dismantling. A buyer can also decline the dealer’s offer to mark it.3California Legislative Information. California Senate Bill 55 – Vehicles: Catalytic Converters
If your vehicle predates that rule or your converter was never marked, you’ll want to arrange engraving before you try to sell. Some law enforcement agencies and community groups hold free or low-cost VIN-etching events, and aftermarket services offer the same thing. Without that mark, a legitimate recycler has no legal path to buy from you.
How You’ll Be Paid
Don’t expect cash. California prohibits core recyclers from paying cash for catalytic converters, and for individual sellers there is an added delay built into the statute.3California Legislative Information. California Senate Bill 55 – Vehicles: Catalytic Converters
The recycler must either mail your payment to your address or hold it for you to collect on the third business day after the sale. Commercial sellers can receive immediate payment by check or by debit or credit card, but individuals cannot. The waiting period is deliberate: it gives law enforcement a window if the converter turns out to be stolen, and it discourages anyone looking for quick anonymous cash.3California Legislative Information. California Senate Bill 55 – Vehicles: Catalytic Converters
What the Recycler Will Write Down About You
Business and Professions Code 21610 requires the recycler to create a written record of every converter transaction and keep it for at least two years, available to law enforcement on request. For an individual seller, the record includes your name, your driver’s license or state ID number and its state of issue, and the license plate of the vehicle you drove to the recycler.2California Legislative Information. California Code Business and Professions Code BPC 21610
The transaction record also captures the date and location of the sale; a description of the converter including type, quantity, and any identification number; the amount paid; and the year, make, model, and VIN of the vehicle the converter came from. You’ll sign a statement confirming ownership, or identifying who you got it from if you didn’t remove it yourself.2California Legislative Information. California Code Business and Professions Code BPC 21610
None of this is optional on the recycler’s side. A clerk who skips any of it is risking a misdemeanor and, on repeat violations, a court-ordered shutdown of the business.2California Legislative Information. California Code Business and Professions Code BPC 21610
What Happens If You Show Up Without the Paperwork
You won’t be sold to. Buying from an unauthorized seller is an infraction under Vehicle Code 10852.5, carrying a $1,000 fine for a first offense, $2,000 for a second, and $4,000 for a third or later offense.1California Legislative Information. California Code Vehicle Code VEH 10852.5 A recycler isn’t going to accept that risk because you forgot your registration or your converter was never marked. Loose converter, no title, no ID, no VIN match: the sale doesn’t happen.
A few boundaries worth being clear about. These rules govern selling a converter as a loose part. They don’t cover trading in a whole vehicle to a dealer or dismantler, where the converter travels with the car. And if you removed the converter from a vehicle you don’t own, nothing in this framework authorizes the sale, regardless of what paperwork you can produce for the car itself.
If the pieces line up — your title, a matching VIN engraved on the converter, your ID, and a licensed core recycler — the transaction is straightforward. You just won’t be walking out with cash in hand.