CAP Clean, Retail, Average and Below: Trade Values Explained for UK Dealers

Last updated 29 September 2026.

“What’s it worth, clean?” is one of the most common questions in the trade, and the answer usually comes from CAP HPI. CAP clean, average and below are trade values for the same car in three conditions, and CAP retail is what the car is likely to be advertised for. This guide explains what each figure means, where Glass’s fits in, how mileage and condition move the numbers, and how to use trade values alongside AutoTrader’s retail valuation to decide what to pay and what to ask.

This guide is based on CAP HPI’s and J.D. Power’s published material as of September 2026. Guide products, definitions and prices change, so check the linked sources before relying on a detail.

What are CAP HPI and Glass’s?

CAP HPI and Glass’s are the two long-standing UK trade price guides: independent companies that publish what used cars are worth to the motor trade. When dealers talk about “book” or “under book”, they mean one of these guides. Our A to Z of motor trade jargon covers the slang. For bikes, see how to value a used motorbike.

CAP HPI (now part of Solera) publishes several “books”. The ones dealers meet most are:

• Black Book, which CAP HPI describes as the industry benchmark for used car disposal values. It gives a suggested retail price, trade values at clean, average and below average, and mileage variations (CAP HPI: Black Book).
• Black Book Live, the real-time version, which shows live values alongside the retail, clean, average and below average figures and adds a comment explaining why each value changed (CAP HPI: Black Book Live questions and answers).
• Gold Book, which forecasts vehicle values up to five years ahead. CAP HPI lists lenders, fleet operators, manufacturers and dealers among its users, who use it to plan ownership and finance decisions (CAP HPI: Gold Book).

CAP HPI says Black Book data is used by dealers and traders, fleet, leasing and rental companies, motor insurers, and auction and remarketing businesses (CAP HPI: Black Book used car values). That is why the same figures turn up in part-exchange offers, finance decisions and insurance settlements.

Glass’s has been published since 1933, when William Glass produced the first guide, and became known in the trade as “the bible” (Wikipedia: Glass’s Guide). It became part of Autovista Group, which J.D. Power bought in March 2024 alongside Eurotax and Schwacke (J.D. Power: completion of Autovista Group acquisition). Glass’s own website, glass.co.uk, now redirects to J.D. Power.

CAP retail, clean, average and below: what each value means

CAP retail is a forecourt figure. Clean, average and below are trade figures for the same car in three conditions. That is the whole difference, and mixing them up is the most expensive mistake on this list.

CAP retail

CAP retail is what the car is likely to be advertised for by a dealer. CAP HPI says its retail values reflect live dealer adverts that it analyses every day from the main advertising websites, over 700,000 unique adverts a day (CAP HPI: vehicle retail values). It assumes a prepared car on a forecourt, so you cannot pay CAP retail for a car and make money on it.

CAP clean, average and below

CAP HPI publishes vehicle condition standards that decide which trade value applies. The bodywork allowance grows with age, so a clean eight-year-old car can have more SMART repairs than a clean one-year-old. For every age, the standards say:

Note that CAP clean is about condition. It is not the same as a car being “clean” on a history check, which in forecourt slang means no outstanding finance, write-off or theft record. A car can be CAP clean and still have a Cat S record, so run the history check as well. Our guide to Cat S and Cat N write-offs covers what that means.

How mileage and condition change the value

Mileage and condition are the two biggest adjustments. CAP HPI says that entering the mileage in Black Book Live adjusts the value automatically, and Black Book includes mileage variations for each model. Always value on the actual mileage, not the average for the age, because a high-mileage car can sit well below the headline figure.

Condition decides which of the three trade values you use. Grade the car honestly against the standards above, then take off the cost of any work it needs to reach the standard you plan to sell it at. The guide assumes the condition. It does not know about the two kerbed alloys, the missing spare key or the warning light you found on the test drive. Our vehicle appraisal best practices cover what to check.

Specification matters too. CAP HPI says Black Book analyses mileage, technical and spec data to reach a current value, so look the car up by registration or VIN rather than picking a derivative by hand.

Trade price, retail price and part-exchange price

A trade price is what one trader would pay another. A retail price is what a member of the public pays for a prepared car on your forecourt. A part-exchange price is what you agree to give a customer for their car against one they are buying from you.

• Trade price. CAP clean, average and below are trade prices, and AutoTrader’s trade valuation is what it says a car is worth sold between dealers, effectively without margin. It is your guide to what a car is worth at auction or to another dealer.
• Retail price. CAP retail and AutoTrader’s retail valuation are both retail figures. The gap between trade and retail has to pay for preparation, warranty, advertising, holding costs, VAT and your profit.
• Part-exchange price. This is a negotiated figure. It usually starts from a trade value adjusted for condition, and AutoTrader also publishes a separate part-exchange valuation. Whatever you allow for the part exchange, the car still has to earn its place: if you would trade it out, it is worth what the trade will pay, less transport and fees.

Customers often come in with a private-sale or retail figure from a free online valuation. Showing them the trade value and the work the car needs usually makes the conversation easier.

How CAP values relate to AutoTrader valuations

CAP values and AutoTrader valuations answer similar questions using different data, so treat them as two opinions rather than one right answer. AutoTrader’s retail valuation is built from the advertised prices of similar cars on AutoTrader over the last 28 days and drives the price label buyers see on your advert. We explain it in detail in our guide to AutoTrader valuations for dealers, including the retail rating, which tells you how quickly a car is likely to sell in your area.

In practice, many dealers use them like this:

• AutoTrader retail valuation to set the advertised price, because that is the number your price label is measured against.
• CAP clean, average or below to sense-check what you pay, and to know what the car will fetch if it does not sell and goes to auction.
• AutoTrader retail rating to decide whether a car is worth buying at all at that price in your area.

If CAP retail and AutoTrader retail are far apart for the same car, check the spec and mileage entered in both before you trust either.

Worked example: setting a buying price and a retail price

The safest way to set a buying price is to work back from the retail price, then compare the result with the trade values. All the figures below are illustrative. Use your own costs and the live values for the car in front of you.

Say you are offered a five-year-old hatchback. The illustrative values are: AutoTrader retail valuation £12,500, CAP retail £12,300, CAP clean £10,400, CAP average £9,800 and CAP below £8,900.

The VAT line assumes you are VAT registered and sell under the margin scheme, where VAT is one-sixth of the difference between what you paid and what you sell for. HMRC says that purchase price does not include preparation, repairs or overheads, so the margin here is £12,500 less £10,160, which is £2,340 (GOV.UK: using the VAT margin scheme for second-hand vehicles). Our VAT margin calculator and vehicle profit calculator do the sums for you.

Now compare £10,160 with the trade values. The car has a full service history and its scuffs are within the clean allowance for its age, but it needs two tyres, so it grades as average: £9,800. If it had more damage than the average allowance, it would grade as below: £8,900. Your maximum is above trade, so buying at or near CAP average leaves room for your profit. If the seller wants £10,800, above CAP clean and above your maximum, you would be paying more than the trade would, and more than the retail price can support.

For the retail price, start at the AutoTrader retail valuation with the full spec recorded, and use the retail rating to decide how hard to price it. CAP retail is a useful second opinion.

Why values differ between guides

CAP HPI, Glass’s and AutoTrader will rarely give the same figure for the same car, for a few reasons:

• Different data. CAP retail is built from live dealer adverts across advertising websites, while AutoTrader’s retail valuation uses adverts on AutoTrader.
• Editorial judgement. CAP HPI says its values are set by a team of editors who research values and trends in the market.
• Different condition grades. CAP uses clean, average and below. AutoTrader’s trade, part-exchange and private valuations use condition bands from Excellent to Poor.
• Timing. A value updated this morning and one updated last week can differ in a moving market.
• Spec and mileage. The wrong derivative, missing options or an estimated mileage will throw any guide out.

How often CAP values update

CAP values change all the time. CAP HPI publishes Black Book monthly and says daily updates between publications give access to more than six million trade value movements (CAP HPI: trade values). Black Book Live updates in real time. A printed or saved value from last month is out of date, so look the car up again on the day you buy.

Access has become easier for small traders. In August 2026, Motor Trader reported that Solera CAP HPI had launched a self-service Black Book Starter plan for smaller independents, priced at £87.63 a month (excluding VAT) billed annually, including 150 registration look-ups a year (Motor Trader: Solera CAP HPI opens Black Book valuations to smaller independents).

Common mistakes

Mistake	What to do instead
Paying CAP retail for a car you need to sell on	Retail is a forecourt price. Buy against trade values and work back from retail.
Grading every car as clean	Check it against CAP HPI's condition standards, including service history, keys and tyres.
Valuing on an estimated mileage	Enter the actual mileage. It changes the value.
Picking the derivative by hand	Look the car up by registration or VIN so the spec is right.
Using last month's value	Look the car up again on the day. Values move daily.
Forgetting VAT on the margin	If you are VAT registered, one-sixth of your margin goes to HMRC. Build it in before you set your maximum.
Treating one guide as the truth	Compare CAP with AutoTrader and check the retail rating before you commit.

How Haswent helps

If CAP HPI is switched on for your account, Haswent shows CAP retail, clean, average and below figures on the vehicle, appraisal and part exchange screens. You can look a car up by registration or CAP ID, and value single cars, or paste in a list of registrations and mileages, under Stock > Valuations. You do not need your own CAP HPI licence, and valuations are charged per vehicle. With AutoTrader connected, the AutoTrader valuations sit on the same car, so you can compare them side by side.

Read more about the CAP HPI integration and online appraisals, or contact us for a demo.

Sources

• CAP HPI: vehicle condition standards (PDF)
• CAP HPI: Black Book
• CAP HPI: Black Book Live questions and answers
• CAP HPI: Black Book used car values
• CAP HPI: vehicle retail values
• CAP HPI: trade values
• CAP HPI: Gold Book
• Motor Trader: Solera CAP HPI opens Black Book valuations to smaller independents (4 August 2026)
• J.D. Power completes Autovista Group acquisition (1 March 2024)
• Wikipedia: Glass's Guide
• GOV.UK: using the VAT margin scheme for second-hand vehicles

Frequently asked questions