Speed Camera Tolerance – How Much Over the Limit Is Allowed?

Speed Camera Tolerance – How Much Over Can You Go?

You’ve probably heard the saying: “You’re allowed 10% over the speed limit, plus 2 mph.” But is that true? Or is it just one of those myths that’s been passed around for years?

Let’s clear it up. Here’s how speed camera tolerances work in the UK — what the guidelines say, what’s actually enforced, and when you’re likely to be hit with a fine.

Is there an official tolerance?

Technically, no — there’s no legal rule that says you’re allowed to go over the limit by a certain amount. The speed limit is the absolute maximum, and going even 1 mph over it is breaking the law.

However, most police forces follow guidance from the National Police Chiefs’ Council (NPCC), which recommends a buffer to account for speedometer inaccuracies and human error.

What’s the ‘10% + 2 mph’ rule?

This is the informal guideline most forces use. It means you might not be penalised unless you're doing:

• 35 mph in a 30 zone

• 46 mph in a 40 zone

• 57 mph in a 50 zone

• 68 mph in a 60 zone

• 79 mph in a 70 zone

So, for example, if you’re doing 34 in a 30 zone, you’ll probably be fine. But push it to 36 and you’re into ticket territory.

That said, this isn’t law — it’s discretion, and it varies slightly between police forces and camera types.

Does it apply to all speed cameras?

Not always. There are several types of speed cameras used in the UK — including:

• Fixed speed cameras

• Mobile speed cameras (in vans or roadside)

• Average speed cameras

• Red light/speed-on-green cameras

Most fixed and average speed cameras follow the NPCC’s 10% + 2 guideline. But mobile cameras? They’re known to be less forgiving — and they can catch you even a couple of mph over the limit.

Can I be fined for going 31 in a 30?

Yes — in theory. But in practice, that’s unlikely. Most forces won’t issue a fine unless you’re at least hitting that 10% + 2 threshold.

Still, that doesn't mean you're safe to treat the limit as a target you can push. Speed limits are set for a reason — and enforcement is ultimately up to each local force.

What happens if I do get caught?

If you’re caught just over the limit, you might be offered a speed awareness course (as long as you haven’t done one recently). Otherwise, you’ll typically get:

• A £100 fine

• Three penalty points on your licence

For more serious offences (i.e. way over the limit), you could face a higher fine, more points, or even a court appearance and a ban.

The takeaway

That “10% + 2” buffer? It’s a guideline, not a guarantee. You could still be fined for going over the limit — even slightly — especially if you’re unlucky or the camera doesn’t follow the standard rules.

So the best bet? Stick to the limit. Not just to avoid fines, but to keep yourself and everyone else on the road safe.

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