You can challenge a prohibited turn PCN by making representations to the issuing authority within 28 days, and appealing free of charge to an independent adjudicator if it is rejected. The grounds that succeed most often are: the no-turn sign was not compliant or not visible in time, the sign did not match the traffic order behind it, the turn did not actually happen as alleged, the manoeuvre was forced by an emergency, or the camera evidence does not establish the turn.
Banned turns are enforced entirely by camera at junctions chosen because they catch a lot of drivers. High volume is exactly where defective signs and weak footage hide.
The rule, precisely
A prohibition on turning is only enforceable if it is signed correctly. The sign must conform to the Traffic Signs Regulations and General Directions 2016: Diagram 612 for No Right Turn, Diagram 613 for No Left Turn. It must be the prescribed size and retroreflective specification, and positioned so a driver approaching normally can see and react to it before the point where they must commit to the turn.
The prohibition also has to be authorised by a Traffic Regulation Order made under the Road Traffic Regulation Act 1984. The physical sign on the street must match that order, including any hours of operation. If the sign says one thing and the order says another, the restriction is not properly made out.
The contravention enforced by councils is code 50: performing a prohibited turn. Read it literally. The council is not proving you were near the junction. It is proving you made a specific banned turn, warned by a lawful sign, at a location where a valid order prohibits it.
Who can fine you
In London, boroughs and Transport for London have enforced banned turns by camera for years under the London Local Authorities and Transport for London Act 2003. Outside London, councils gained the same power from 31 May 2022 under Part 6 of the Traffic Management Act 2004, but only once granted a Designation Order for the location. The wider framework, deadlines and appeal routes are set out in the moving traffic PCN guide.
The grounds that succeed
1. The sign was not compliant or not visible in time.
This is the ground that wins most banned-turn cases. If the No Right Turn or No Left Turn sign was obscured, undersized, wrongly positioned, missing, or simply not visible from your approach until it was too late to comply, the warning the law requires was never given. Photograph the approach from the driver\'s seat height, early, before anything is quietly fixed.
2. The sign did not match the traffic order.
Ask the authority to produce the Traffic Regulation Order and confirm the sign reflects it exactly, including the hours the turn is banned. Orders and signs drift apart over the years. A mismatch on timing or scope is a recognised ground.
3. The turn did not happen as alleged.
If you went straight through, or the enforcement footage shows a different vehicle or registration, the contravention did not occur. Dashcam footage of your actual route is powerful here.
4. The turn was forced.
An emergency vehicle, an obstruction that appeared without warning, or a road condition that made any other course unsafe. A specific, footage-consistent account of why you had no lawful alternative invites the authority to use its discretion.
5. The evidence does not prove the turn.
The camera must be an approved device under the Civil Enforcement of Road Traffic Contraventions (Approved Devices, Charging Guidelines and General Provisions) (England) Regulations 2022 (SI 2022/71). The footage must show the turn itself and the direction of travel unambiguously. Stills that could be consistent with a permitted manoeuvre do not discharge the authority\'s burden of proof.
Challenge your banned turn PCN with the right letter
The Code 50 Prohibited Turn Challenge Letter covers sign compliance, the traffic order, direction-of-travel evidence and the camera certification. £15.
What does not work
- “The sign is easy to miss.” Reframe it. If it was genuinely not visible in time, that is a signage-compliance ground. “Easy to miss” on its own reads as an admission.
- “I’m not from the area.” Local knowledge is not the test. A compliant, visible sign binds every driver equally.
- “There was no other way to my destination.” Inconvenience is not a defence unless a genuine emergency left you no safe option.
- An apology and an account of your day. Case officers cannot cancel a penalty out of sympathy. Give them a legal reason.
Put the authority to proof
A banned-turn challenge is a signage and evidence case. The representations that succeed identify exactly which element the authority cannot prove, cite the correct diagram and regulation, and demand the traffic order and the full footage that decide it. Related signage points are covered in the defective signs and road markings guide, and the closely related restriction is the no entry PCN.
The Code 50 Prohibited Turn Challenge Letter is built on those grounds, with the traffic-order and evidence demands included, for £15.
The letter for this
Council PCN Code 50, Performing a prohibited turn
Written for this specific ground, with the law cited and the evidence demands built in. Complete the placeholders and send it.
Included free with the letter
- How to Submit Your Tribunal Appeal
- How Council Parking Appeals Work
Frequently asked questions
What is a code 50 PCN?
Code 50 is the moving traffic contravention for "performing a prohibited turn". It covers turning right or left where a No Right Turn or No Left Turn sign applies, and turning where a no U-turn restriction is in force. It is a civil penalty enforced by camera, not a criminal offence, so there are no points and no effect on your insurance.
What sign does the council have to prove was there?
A prohibited turn must be signed with a sign conforming to the Traffic Signs Regulations and General Directions 2016: Diagram 612 (No Right Turn) or Diagram 613 (No Left Turn). The sign must be the correct size and reflectivity, and positioned so an approaching driver can see it in time to comply, before the point of decision at the junction.
The sign was hidden by a tree. Is that a defence?
Yes, potentially a strong one. A restriction is only enforceable if the sign is actually visible to a driver approaching in the normal way. A No Right Turn sign obscured by vegetation, a parked lorry, scaffolding or another sign cannot give the warning the law requires. Photograph the approach from a driver's eye line as soon as you can, because councils cut back vegetation and reposition signs after complaints.
Can they fine me if the camera footage does not clearly show the turn?
The authority carries the burden of proving the contravention. The camera must be an approved device under SI 2022/71, and the footage must show your vehicle actually performing the prohibited turn, not merely being near the junction. Footage that is consistent with a permitted manoeuvre, or that does not clearly establish the direction of travel, is not enough.
I only turned because the road ahead was blocked. Does that help?
It can. Where a genuine emergency or a road condition left you no safe alternative, set out exactly what happened and invite the authority to exercise its discretion. It is not an automatic win, but a specific account consistent with the footage is treated very differently from a general complaint.
How long do I have to challenge?
The PCN arrives by post and states your deadlines. You normally have 28 days to make representations, and paying the discounted amount ends your right to challenge. If the authority rejects your representations, you have 28 days to appeal free of charge to the Traffic Penalty Tribunal (outside London) or London Tribunals (in London).
Make the council prove the sign and the turn.
The Code 50 Prohibited Turn Challenge Letter covers sign compliance, traffic-order mismatch, direction-of-travel evidence and camera certification.