What is the 'Six-Month Rule' when buying a used car in the UK?

Under the Consumer Rights Act 2015, the 'Six-Month Rule' is a legal presumption that any fault appearing within the first six months of ownership existed at the time of delivery. This means the burden of proof lies with the motor trader to prove the vehicle was not faulty when sold.

What are my rights if my used car develops a fault within 30 days?

If a mechanical or software fault is found within the first 30 days of purchase, you have a 'short-term right to reject' the vehicle. You are entitled to a full refund from the dealer and do not have to accept a repair or replacement.

Do I have to let the dealer repair my car under the Consumer Rights Act?

After the first 30 days but within the first six months, the dealer must be given one opportunity to repair or replace the vehicle. If the repair fails or is impossible, you can then exercise your 'final right to reject' for a refund (though the dealer may deduct for usage).

Does the Consumer Rights Act 2015 apply to private car sales?

The Consumer Rights Act 2015 applies to vehicles purchased from professional motor traders. It does not cover private sales, where the principle of 'caveat emptor' (buyer beware) applies, and the car only needs to be 'as described'.

Are software faults and EV batteries covered by the Six-Month Rule?

Yes, the CRA 2015 covers software glitches and battery degradation in electric vehicles (EVs). If the software or battery does not meet 'satisfactory quality' or 'fit for purpose' standards within six months, the 'burden of proof' remains with the dealer.

How do I prove a used car fault under the Six-Month Rule?

To claim under the CRA 2015, you should provide the dealer with a clear description of the fault, any diagnostic reports, and proof of purchase (such as a sales receipt or V5C transfer). Since the 'burden of proof' is on the dealer within six months, they must provide evidence if they claim the fault was caused by your misuse.

Used Car Faults: Proving the 'Six-Month Rule' Under CRA 2015 in 2026

The year 2026 continues to see a complex second-hand car market in the UK. While vehicle technology has advanced, the legal framework protecting consumers remains anchored in a powerful piece of legislation: the Consumer Rights Act 2015 (CRA 2015).

If you have purchased a used car that has developed a mechanical fault, you may have heard of the "Six-Month Rule." This is arguably the most significant protection available to car buyers, yet it is often misunderstood by both consumers and motor traders. Understanding how the burden of proof shifts during this period is essential for securing a repair, replacement, or refund.

What is the 'Six-Month Rule'?

Under the CRA 2015, any goods sold by a trader to a consumer must be of "satisfactory quality," "fit for purpose," and "as described." When a used car fails to meet these standards, the Act provides a tiered system of remedies.

The "Six-Month Rule" refers to Section 19(14) and Section 19(15) of the Act. It stipulates that if a fault comes to light within the first six months of ownership, it is legally presumed that the fault (or the developing cause of the fault) existed at the time of delivery.

In 2026, as vehicles become more reliant on complex software and integrated batteries, this rule is more relevant than ever. It effectively reverses the "burden of proof," placing the responsibility on the dealer to prove the car was not faulty when it left the forecourt.

Buyer Rights: Your Protections When Things Go Wrong

As a buyer in 2026, your rights are determined by the timeline of when the fault is discovered.

1. The Short-Term Right to Reject (First 30 Days)

If a fault is discovered within the first 30 days of purchase, you have the "short-term right to reject." You are entitled to a full refund and are not legally required to allow the dealer to attempt a repair. This is an absolute right under the CRA 2015, provided the fault makes the car of unsatisfactory quality.

2. The Burden of Proof (The 6-Month Window)

If the fault appears after 30 days but before six months have passed, the "Six-Month Rule" applies. At this stage:

The Presumption: The law assumes the fault was present at the point of sale.
The Remedy: You must give the dealer one opportunity to repair or replace the vehicle. You cannot demand a refund immediately unless they fail to fix the issue or if the repair is impossible.
The Cost: The repair must be carried out at no cost to you, including labor and parts.

3. Protection Under Section 75 (Consumer Credit Act 1974)

If you paid for even a portion of the car (between £100 and £30,000) using a credit card or a point-of-sale finance agreement (PCP/HP), you have additional protection. Under Section 75 of the Consumer Credit Act 1974, the finance provider is "jointly and severally liable" for any breach of contract or misrepresentation by the dealer. This means if the dealer goes bust or refuses to help, you can Pecursue the bank for your money back.

4. Voluntary Termination (Section 99)

If you are struggling with a faulty car on finance and have paid off at least 50% of the total amount payable, you may have the right to "Voluntary Termination" under Section 99 of the Consumer Credit Act 1974. While this isn't a remedy for a fault per se, it is a statutory right that can provide an exit route in certain financial circumstances.

Dealer and Trader Obligations: The Legal Framework

Dealers often attempt to bypass the CRA 2015 by claiming a "sold as seen" status or relying solely on a three-month third-party warranty. In 2026, these tactics remain legally invalid in consumer-to-business transactions.

1. Proving the Negative

To successfully defend a claim within the first six months, the trader must prove that the fault was caused by:

Abnormal wear and tear: Considering the age and mileage of the car.
Accidental damage: Occurring after the sale.
Misuse: For example, using the wrong fuel or ignoring dashboard warning lights.
External Factors: Such as stone chips or environmental damage.

If the dealer cannot prove one of the above, they are legally obligated to provide a remedy.

2. Transparency and the CPRs 2008

Under the Consumer Protection from Unfair Trading Regulations 2008 (CPRs), traders are prohibited from misleading consumers or omitting "material information." If a dealer knew a car had a history of transmission issues and failed to disclose it, they are in breach of these regulations. This can be used alongside the CRA 2015 to bolster a claim for a refund.

3. Roadworthiness and the Road Traffic Act 1988

It is a criminal offence under Section 75 of the Road Traffic Act 1988 to sell a vehicle in an unroadworthy condition. If a dealer sells a car with bald tyres, failing brakes, or structural rust that makes it dangerous, they are not only liable for a civil claim under the CRA 2015 but may also face prosecution.

4. Financial Conduct Authority (FCA) Compliance

Since used car dealers often act as credit brokers, they must adhere to the Financial Services and Markets Act 2000 (FSMA). If a dealer pressured you into a finance deal for a vehicle they knew was substandard, they may be in breach of FCA "Treating Customers Fairly" (TCF) outcomes.

How to Prove a Fault in 2026

While the law favors the consumer in the first six months, you still need to be proactive.

Independent Inspection: If a dealer disputes your claim, an independent report (e.g., from the AA, RAC, or a marque-specific specialist) can provide the technical evidence needed to show the fault is inherent and not due to wear and tear.
Documentary Evidence: Keep copies of the original advertisement, the sales invoice, and any correspondence. In 2026, screenshots of digital listings are vital, as they often contain "as described" promises.
The "One Repair" Rule: Remember, after 30 days, the dealer has one chance to fix it. If the repair fails, or the car is still faulty, you can then trigger your "Final Right to Reject" for a refund (though a deduction for the usage you’ve had may be applied).

Key Takeaways for 2026

0–30 Days: You have a short-term right to reject a faulty car for a full refund.
30 Days–6 Months: The "Six-Month Rule" means the dealer must prove the car wasn't faulty at the time of sale. You must allow one attempt at repair.
After 6 Months: The burden of proof shifts to you. You must prove the fault was present at the time of sale.
Traders Only: These rights apply when buying from a business. Private sales are governed by the principle of Caveat Emptor (Buyer Beware), though the car must still be "as described."
Warranty vs. Law: A dealer warranty is an addition to, not a replacement for, your statutory rights under the CRA 2015.

Disclaimer: This article provides general information regarding UK consumer law as of May 2026. It does not constitute legal advice. If you are involved in a dispute, you should consult with a qualified legal professional or contact Citizens Advice.