The truth about car park cameras

Automatic Number Plate Recognition (ANPR) cameras are increasingly used in car parks, petrol stations and on the roads more generally to monitor wrongdoing. But these cameras aren't always reliable.

Even at an estimated accuracy rate of around 97% – as cited by Fraser Sampson, a former Home Office biometrics and surveillance camera commissioner – that's more than two million inaccurate reads per day.

And these inaccurate reads all too often result in unfair Parking Charge Notices (PCNs), debt-collection threats and customer service headaches for innocent motorists.

From 'double dipping' to numberplate fraud, we examine the pitfalls of ANPR technology and how to fight an unfair PCN.

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ANPR Double-dipping errors

For drivers who regularly visit the same car park in a short space of time – perhaps to go to the supermarket or take a family member to the station – double dipping is one of the most common ANPR-related gripes.

This occurs when you visit a car park on two separate occasions, but the ANPR cameras don't record your first exit or second entrance onto the site. Drivers who fall victim to this will likely be issued a PCN for overstaying.

Which? senior researcher James Aitchison experienced this last year, receiving two erroneous PCNs within three months. Both were issued after he had dropped off his partner at a train station on two subsequent days.

'It was the result of double dipping, as the camera didn't register me leaving the car park on one day or entering the car park the following day,' James explained.

He challenged both PCNs using the free Which? letter template to contest a parking fine and was successful. But the onus was on James to provide evidence that he hadn't stayed overnight, rather than on the parking firm to prove he had.

Putting together the evidence wasn't easy, either: 'I ended up using the Google Location data on my phone. I provided screenshots of my location on the relevant days, as well as train ticket stubs to show my whereabouts,' he said.

• Read more: Which? calls for tougher parking fine rules to stop unfair charges

Camera installation issues

Badly installed cameras are part of the problem. If cameras aren't set up properly – perhaps they're installed in a high-up position or are angled downward – it can lead to misreadings.

Incorrect PCNs may also be issued if a driver's numberplates are masked by the car in front.

Which? member John, from Gloucestershire, was wrongly issued four fines after a poorly installed camera in a nearby car park picked up his registration plate while driving past the site during a holiday.

John hadn't been notified of the fines at the time they were issued in 2024; he only found out about them after paying a legitimate parking fine on the private parking firm's website in January of this year.

He told us: 'After a lot of digging in my records, I recalled that I had rented a holiday cottage near Swanage in 2024, which had a narrow access road that passed a car park, which was ANPR checked. Looking on Google Street View, I could see that the ANPR camera from the car park was positioned in such a way that it had detected my car as it drove past on the way to the cottage.'

John then looked for charges against his son, who had also been staying in the cottage, and found that he had even more PCNs listed against his car. Again, John's son hadn't been notified about them.

After some back and forth, the parking firm removed all the charges.

• Read more: how to challenge a PCN

Numberplate fraud

Licence plate fraud, in which a car's number plates are cloned to avoid ANPR detection, is also leading to unfair fines.

These rogue drivers might then overstay in car parks, fill up with petrol without paying or drive fee-free through congestion zones.

Eric Lytra received nine PCNs from Horizon Parking between March and October 2025, after his numberplate was cloned.

'The rogue car used two black tape strips on the L to change it to an E, so it mirrored my registration. Each fine was due to the car overstaying at a Tesco car park,' Eric said.

He appealed the fines and reported the issue to the police, the DVLA and his insurance firm. Despite this, he continued to receive more PCNs.

'The whole saga only really ended when I managed to get the police, after all that time, to contact the offender, warning that action would be taken if they persisted,' Eric explained. The criminal then finally stopped.

Horizon Parking told us that while ANPR systems are highly effective, it can be challenging to identify deliberately altered or cloned number plates from captured images alone.

It advises you to report these issues to the police, and says that where it finds credible evidence of cloning or tampering, it won't pursue the PCN.

Councils write off fines due to cloned plates

Which? sent Freedom of Information (FOI) requests to the councils that issue the most parking fines, asking them how many PCNs they've had to cancel due to a numberplate having been cloned.

Of the five councils that responded to our FOI requests, three saw the number of fines cancelled as a result of cloned plates rise year on year since 2023.

London's Hackney, Islington and Harringay boroughs had the most instances of cloned plates. Hackney cancelled 5,082 PCNs last year due to cloned plate fraud, while Islington cancelled 2,756 and Harringay wrote off 2,581.

Manchester's cancelled fines were up by 147% from 2023, while Cardiff's increased by 122%, and the London Borough of Islington's were up by 45%.

Similarly, FOI data from Transport for London revealed that 9,081 Ultra Low Emission Zone (ULEZ) fines were cancelled last year due to cloned plates.

More regulation needed

In December last year, the All-Party Parliamentary Group for Transport Safety Group (APPGTS) published a report on the UK's outdated numberplate system.

Concerningly, it noted that there are 34,455 numberplate suppliers registered with the Driver and Vehicle Licensing Agency (DVLA), with no background checks in place.

Some suppliers handling customers' IDs were even found to have serious criminal convictions, including fraud.

The report gave several recommendations on how to combat this type of fraud, including standardising the design of registration plates in line with international standards, and banning 3D and 4D plates, which can distort ANPR readings.

Crucially, the APPGTS wants to significantly restrict the number of licensed sellers via annual fees, regular audits and removal of non-compliant sellers. It's proposed that the fine for those with illegal plates, which is currently only £100, should be increased and that offenders should be given points on their driving licence.

Which? wants higher standards

The number of privately issued parking fines continues to rise. These fines often feel disproportionate and unfair. 

The government is introducing a new Private Parking Code of Practice, which will replace the industry's self-set code.

It first proposed this Code in February 2022, but it was withdrawn later that year after the industry issued legal proceedings against proposals to change maximum fines and ban additional fees.

In September 2025, the government launched a consultation on the Code. Which? responded, calling for tougher measures to be included to curb unfair PCNs. Some of these measures include standardised signage across car parks, a ban on debt recovery fees and an independent single appeals service to improve the appeals process.

We also want a ban on parking charges issued to motorists who pay for their stay in full before leaving an ANPR car park. This means if you experience delays making your payment, beyond the five-minute grace period typically offered, Which? believes you should not receive a PCN.