The car and its papers
Log book (V5C)
The vehicle registration certificate DVLA issues — GOV.UK calls it the “V5C certificate (vehicle log book)”. A replacement usually costs £25. (GOV.UK) Its 11-digit number is used, for example, to make a SORN online and to see where each MOT test was done. (GOV.UK, SORN) (GOV.UK, MOT history)
SORN
GOV.UK: “Tell DVLA you’re taking your vehicle off the road, for example if you’re keeping it in a garage. This is sometimes called a ‘Statutory Off Road Notification’ (SORN).” Full months of remaining tax are refunded, and the vehicle can't be used on the road until it is taxed again. A vehicle already sold doesn't need a SORN — DVLA is told it has been sold instead. (GOV.UK)
Vehicle history check (“HPI check”)
A paid check on a vehicle's past, sold by several companies — “HPI check” is a common name for one, after one of them. The Department for Transport describes a private history check as one that “will tell you if the vehicle has been stolen, has outstanding finance, has a mileage discrepancy or has previously been written off”. (Department for Transport)
VIN
The vehicle identification number. The Department for Transport's buyer guide lists checking that the VINs on the vehicle agree with each other and with the VIN in the log book, and says the VIN, as well as the registration number, can be used for a history check. (Department for Transport)
MIAFTR
The Motor Insurance Anti-Fraud and Theft Register, kept by insurers. The AA: when a stolen vehicle is recovered undamaged or with minor damage, MIAFTR “must be alerted, so they can mark the vehicle as recovered”. (The AA)
Write-offs
Write-off
When a damaged vehicle is written off, the insurer pays the owner its current value instead of the cost of repairing it. The insurance company decides whether it is written off. (GOV.UK)
Cat A, B, S and N
Today's categories. A: cannot be repaired, the whole vehicle is crushed. B: cannot be repaired, the body shell is crushed but other parts can be salvaged. S: can be repaired following structural damage. N: can be repaired following non-structural damage. S and N can be used again once repaired to a roadworthy condition. (GOV.UK) More: Write-off categories explained, Cat S, Cat N.
Cat C and Cat D
The repairable categories before 1 October 2017. C: “repairable but repair costs exceed pre-accident value”. D: “repairable but repair costs don't exceed pre-accident value”. (The AA) More: Cat C and Cat D cars.
Actual loss and constructive loss
The two kinds of insurance total loss. Actual loss: a vehicle that cannot or should not be repaired (category A or B), which DVLA won't re-register. Constructive loss: one that could be repaired but where the cost would exceed its replacement value (category S or N). (Department for Transport)
Vehicle Identity Check (VIC)
A check, introduced in 2003, that a written-off car returning to the road matched its registration details, to stop “vehicle ringing”. It cost £41 and ended on 26 October 2015. (Department for Transport)
MOT
MOT history
The record of a vehicle's MOT tests on GOV.UK: whether each passed or failed, the mileage recorded and when the next MOT is due. For cars, motorcycles and vans it covers tests done since 2005. (GOV.UK) More: Car mileage and MOT history.
Dangerous, major and minor
The MOT defect categories. A vehicle fails if the result lists “dangerous” or “major” problems; “minor” problems don't fail it. (GOV.UK)
Advisory
A note on the MOT result: GOV.UK says a vehicle might also get a list of “minor” or “advisory” problems “to monitor or fix in the future”. An advisory doesn't fail the car. (GOV.UK)
Buying and selling
Motor trader
For trade plates, GOV.UK counts a business as a motor dealer, motor trader or vehicle tester if it sells vehicles, manufactures or repairs them, or tests other people's vehicles on public roads. (GOV.UK) For tax, HMRC judges whether buying and selling is trading on the “badges of trade” (below).
Trader and consumer
Under the Consumer Rights Act 2015, a trader is a person acting for purposes relating to their trade or business, and a consumer is an individual acting wholly or mainly outside their trade or business. (s2) More: Sold as seen.
Part exchange
Handing over a vehicle as part of the price of another. GOV.UK's log book has a section headed “sell, transfer or part-exchange your vehicle to the motor trade”. (GOV.UK) For VAT under the margin scheme, the selling price of the car sold isn't reduced by the value of the car taken in. (GOV.UK, HMRC)
Sold as seen
Trading standards' guidance lists “misleading consumers about their statutory rights by using statements such as ‘sold as seen’ or ‘trade sale’” as an example of a misleading action by a trader. (Business Companion) More: Sold as seen.
Trade plates
Number plates DVLA issues with a trade licence, so a motor trader's employees and customers can drive a vehicle the business has for set purposes without registering and taxing it. (GOV.UK) More: Trade plates.
Tax and VAT
Badges of trade
The signs HMRC weighs to decide whether an activity is trading — among them a profit-seeking motive, the number of transactions, changes made to the item to sell it, and the time between buying and selling. No single badge decides it. (HMRC BIM20205) More: Car flipping in the UK.
VAT margin scheme
A way for a VAT-registered business to account for VAT on the difference between what it paid for an eligible second-hand vehicle and what it sold it for, instead of the full selling price: the margin × 1/6. (GOV.UK) More: The VAT margin scheme for used cars.
Stock book
The record the margin scheme needs, tracking “each item sold under the margin scheme individually”: stock number, dates, invoice numbers, purchase and selling prices, seller and buyer, description, margin and VAT due. (GOV.UK)
Qualifying car
HMRC: “a car that's not been subject to the full input tax block” — the business or a previous owner recovered the VAT on its purchase in full — sold “on a normal tax invoice, with VAT charged on the full selling price”. (HMRC, VAT Notice 700/64)