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UK speed camera tolerances revealed

Some speed cameras have tolerances, which means you could go a few mph over the speed limit before you get a fine. This isn't an excuse for breaking the speed limit though.

Tolerances aren't the only thing that's confusing about speed cameras. Many drivers believe that all speed cameras flash. But some catch you with infra-red technology instead. So, no flash doesn’t automatically mean no speeding ticket. Here's what you need to know.

Speed camera over a busy motorway

We contacted 45 UK police forces*. Of the 39 that responded, 26 shared information about when their speed cameras activate if a driver is going above the speed limit.

Most police forces have a tolerance of 10% plus 2 mph above the limit before a speed camera ‘flashes’. So on a 30 mph road, a camera wouldn’t normally activate unless a car drove past at 35 mph or faster. On a 70 mph stretch of motorway, the threshold would go up to 79 mph.

Here’s what the 39 forces responded with:

Police force Speed camera tolerance
Avon & Somerset Police
10% + 2 mph
Bedfordshire Police
Wouldn't reveal threshold
Cambridgeshire Constabulary
Didn’t respond
Cheshire Constabulary
10% + 2 mph
City of London Police
10% + 2 mph
Cleveland Police
Wouldn't reveal threshold
Cumbria Constabulary
10% + 2 mph
Derbyshire Constabulary
10% + 2 mph
Devon & Cornwall Police
Wouldn't reveal threshold
Dorset Police
10% + 2 mph
Durham Constabulary
Wouldn't reveal threshold
Dyfed-Powys Police
Didn’t respond
Essex Police
10% + 2 mph
Gloucestershire Constabulary
10% + 2 mph
Gwent Police
10% + 2 mph
Hertfordshire Police
Didn’t respond
Hampshire Constabulary
Wouldn't reveal threshold
Humberside Police
10% + 2 mph
Kent Police
10% + 2 mph
Lancashire Constabulary
10% + 3 mph
Leicestershire Police
10% + 2 mph
Lincolnshire Police
10% + 2 mph
Merseyside Police
Wouldn't reveal threshold
Metropolitan Police Service
10% + 2 mph
Norfolk Constabulary
10% + 2 mph
Northamptonshire Police
10% + 2 mph
Northumbria Police
Wouldn't reveal threshold
North Wales Police
10% + 2 mph
Nottinghamshire Police
Didn’t respond
North Yorkshire Police
Wouldn't reveal threshold
Police Scotland
10% + 2 mph
Police Service Northern Ireland (PSNI)
10% + 4 mph
South Wales Police
10% + 2 mph
South Yorkshire Police
10% + 2 mph
Staffordshire Police
Wouldn't reveal threshold
Suffolk Constabulary
10% + 2 mph
Surrey Police
Wouldn't reveal threshold
Sussex Police
10% + 2 mph
Thames Valley Police
10% + 2 mph
Warwickshire Police
Didn’t respond
West Mercia Police
10% + 2 mph
West Midlands Police
Wouldn't reveal threshold
West Yorkshire Police
Wouldn't reveal threshold
Wiltshire Police
Wouldn't reveal threshold

But tolerances aren't an excuse for breaking the speed limit. The Metropolitan police said that no matter what the threshold, drivers should always stick to the speed limit and never exceed it.

The speed camera tolerance exists in order to improve driver safety. It means that drivers don’t have their eyes fixed on their speedometer instead of the road.

Average speed cameras are different to normal fixed and mobile speed cameras. Instead of measuring your speed over a short distance, average speed cameras take your speed over several miles.

This means they should be more accurate and so might not have the same tolerance levels as other speed cameras. That being said, all speed cameras should have some kind tolerance built in to account for accuracy.

The typical range of a mobile speed camera van is around 1-2 miles on a straight stretch of road. As you might expect, they can't see through or around bends. The speed detecting technology used also impacts the overall range of the mobile speed camera.

How much over the speed limit can you go before getting a ticket?

Technically, the Association of Chief Police Officers (ACPO) allow a tolerance of 10% + 2 mph on speeding before taking punitive action. 

It’s worth remembering that speed camera tolerances – where they exist – are used at the discretion of the police to follow the rules around speeding, speed cameras, and the law.

So they’re within their rights to punish drivers that break the speed limit by even just a few miles per hour. You can’t rely on these discretionary thresholds as a defence if you’re flagged for speeding. Going even 1 mile an hour over the speed limit counts as speeding, and you could be punished accordingly if caught.

Depending on the severity of the speeding offence, you might:

  • Be offered to take a speed awareness course
  • Get a fine
  • Have points on your licence
  • Be banned from driving

Mobile speed cameras can catch speeding vehicles in either direction, coming towards or away from the speed camera van. Only 1 car can be captured at a time, but the technology is fast. They can usually record a car’s speed quickly and move onto another vehicle.

What are the penalties for speeding in the UK?

If the offence is minor, you might be asked to go on a speed awareness course rather than take the fine and points.

For more serious offences, though, that option isn’t available and the minimum penalty for speeding is a £100 fine and 3 penalty points on your licence.

Speeding fines are based on a percentage of your weekly income, with the minimum fine being £100. For reference, the median weekly UK income last year was £640.

This is in addition to getting points on your licence. Our speeding fine calculator lets you work out any potential fine.

If you've been flashed by a speed camera - whether mobile or fixed, you should get your Notice of Intended Prosecution (NIP) within 14 days of the offence. The NIP is sent to the car's registered keeper. This is taken from DVLA information about the car based on its number plate.

This means you might get a speeding ticket sent to you if one of your named drivers was the one doing the speeding.

Yes - you have to declare any unspent speeding convictions or points on your driving licence to your car insurance company.

Although points remain on your licence for 4 years, insurers use them in their calculations for 5 years.

As a result, you could see your car insurance costs go up up because insurers consider you to be a bigger risk.

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*We issued a Freedom of Information request in February 2023 asking "Is there a speed tolerance on the fixed cameras used in your force area, and if so, what is the tolerance? For example, 10% + 2mph."

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