What Carfax Does and What It Doesn't Tell You
Carfax is a private company that collects and sells vehicle history reports. When you search a used car on Carfax, you get a document that shows accidents, title problems, service records, and ownership changes — but only the ones that were reported to Carfax's network. A car with no accidents in the Carfax report may still have been in an accident that the owner paid for out of pocket, or that a small repair shop never reported.
The report pulls from insurance claims, police reports, DMV records, and service centers that feed data to Carfax. If a fender-bender was never filed with insurance, or if a mechanic fixed it without reporting it, Carfax won't know. This is why Carfax itself says its reports are not a may provide that a car has no damage — they're a record of what was reported.
You can search a car by its Vehicle Identification Number (VIN), which is a 17-character code printed on the driver's side of the windshield and on the title. Carfax charges for full reports, though some dealerships and used car websites include a free Carfax report with their listings.
Key Takeaways
- Carfax reports show reported accidents, title issues, and service history, but they do not catch damage that was paid for privately or repaired at shops that don't report to Carfax.
- You need the car's VIN to search, and you can find it on the windshield, the title, or by asking the seller or dealer.
- A clean Carfax report does not mean a car has no problems — it means no reported problems in Carfax's database.
- Many dealerships and used car listing sites show Carfax reports for free, so check there before paying Carfax directly.
- A Carfax report is one tool among several; a pre-purchase inspection by a mechanic catches problems Carfax cannot.
What Information Appears in a Carfax Report
A full Carfax report includes accident history, title and ownership records, service and maintenance records, and odometer readings. The accident section lists reported collisions, whether the car was declared a total loss, and whether airbags were deployed. The title section shows if the car was ever branded as salvage, flood-damaged, or lemon-law returned.
Service records come from repair shops and dealerships that report to Carfax. These show oil changes, brake service, transmission work, and other maintenance. Odometer readings are tracked across service visits and ownership transfers, which helps detect if the mileage has been rolled back — though this is rare with modern cars.
The report also lists how many owners the car has had and how long each owned it. A car with five owners in three years may indicate chronic problems, though it could also mean the car was used as a rental or fleet vehicle.
How to Find and Read a VIN
The VIN is printed on the lower left corner of the windshield on the driver's side, visible from outside the car. You can also find it on the title document, the insurance card, or the vehicle registration. If you're looking at a car online, the dealer or listing site usually includes the VIN in the ad.
The VIN is 17 characters long and includes letters and numbers. The first three characters identify the manufacturer and country of origin. Characters 4 through 8 describe the car's model, engine, and body type. Character 9 is a check digit used to verify the VIN is real. Characters 10 through 17 are the serial number unique to that specific car.
You do not need to understand the VIN structure to use it — just copy the entire 17-character string and paste it into the Carfax search box. If you type it wrong, Carfax will tell you the VIN is invalid.
Where to Find Free or Included Carfax Reports
Many used car dealerships include a free Carfax report with every listing. Check the dealership's website or the listing on Cars.com, AutoTrader, or Facebook Marketplace — the report is often displayed right on the car's page. If it's not there, you can ask the dealer for it; they usually have it on file.
Some credit unions and auto insurance companies offer free Carfax reports to members. If you're shopping for a car, call your insurance agent or credit union to ask whether they provide this benefit. A few banks also include Carfax access as a perk for checking account holders.
If you cannot find a free report, Carfax charges for single reports and also sells subscriptions that let you run unlimited searches for a month. The price varies, but a single report typically costs between $20 and $30. Compare this cost against the price of a pre-purchase inspection by a local mechanic, which usually costs $100 to $200 but catches mechanical and structural problems Carfax cannot see.
What a Carfax Report Cannot Tell You
Carfax does not inspect the car itself. It cannot tell you whether the engine runs well, whether the transmission shifts smoothly, whether the brakes are worn, or whether the interior is clean. It does not measure rust, check the battery, or test the air conditioning. A car can have a perfect Carfax report and still need thousands of dollars in repairs.
Carfax also misses accidents and damage that were never reported to insurance or police. If an owner hit a mailbox and paid a body shop in cash, Carfax will not know. If a mechanic replaced a fender without reporting it to Carfax's network, the report stays clean. This is why many used car buyers treat Carfax as a screening tool, not a final verdict.
The report also does not cover recalls, though you can search recalls separately on the National Highway Traffic Safety Administration (NHTSA) website using the same VIN. Carfax may mention recalls in some reports, but NHTSA's database is the official source.
How Carfax Compares to Other History Reports
AutoCheck is Carfax's main competitor and uses similar data sources. AutoCheck reports are often cheaper and sometimes catch details Carfax misses, though neither is complete. Some dealers use both reports to cross-check information. If you're buying from a private seller, running both reports costs less than $50 combined and gives you more confidence.
A pre-purchase inspection by a certified mechanic is the most thorough option. The mechanic physically examines the car, test-drives it, and runs a diagnostic scan. This catches engine problems, transmission issues, suspension wear, and hidden damage that no report can find. If you're spending more than $5,000 on a used car, a $150 inspection often saves you thousands in unexpected repairs.
Many buyers use Carfax or AutoCheck first to rule out cars with obvious red flags, then have a mechanic inspect the cars that pass the report check. This two-step approach is faster and cheaper than inspecting every car you look at.
Red Flags to Watch for in a Carfax Report
A salvage title means the car was declared a total loss by an insurance company and then rebuilt. Salvage cars are legal to own and drive, but they are worth significantly less and may have structural damage that affects safety. If a car has a salvage title, get a pre-purchase inspection from a mechanic who specializes in salvage vehicles.
A flood title indicates the car was damaged by water. Flood cars can develop electrical problems, rust, and mold months or years after the damage. A car with a flood title should be inspected thoroughly and priced much lower than a comparable clean-title car.
Multiple owners in a short time, especially combined with accident reports, suggests the car has chronic problems. Lemon-law returns are also a red flag — these are cars that manufacturers bought back because they had persistent defects. If you see a lemon-law return in the report, research what the original problem was before you buy.
Frequently Asked Questions
Can I run a Carfax search without the VIN?
No. Carfax requires the VIN to search. You cannot search by license plate, owner name, or any other identifier. If you don't have the VIN, ask the seller or dealer for it — they are required to provide it.
Does a clean Carfax report mean the car is safe to buy?
A clean report means no accidents or title problems were reported to Carfax, but it does not may provide the car is problem-free. Get a pre-purchase inspection by a mechanic to check the engine, transmission, brakes, and suspension. Carfax and a mechanic's inspection together give you much more confidence than either alone.
How often is Carfax data updated?
Carfax updates continuously as new data comes in from insurance companies, DMVs, and service centers. However, there can be a lag of days or weeks between when an accident is reported and when it appears in Carfax. If you're buying a very recent model, the report may not yet include the latest service records.
What should I do if I find an error in a Carfax report?
Contact Carfax directly through their website and provide documentation of the error. You can also dispute the information with the source — for example, if an accident was reported incorrectly, contact the insurance company or police department that filed the report. Carfax will investigate and correct the report if the error is confirmed.
Is AutoCheck better than Carfax?
Neither is definitively better — they use different data sources and sometimes catch different problems. AutoCheck is often cheaper, and some buyers run both reports to cross-check. For most used car purchases, one report plus a mechanic's inspection is sufficient.