Pick the situation that matches your charge.

For a charge at an airport, port or other land covered by byelaws, where the keeper usually can't be made to pay. Not for National Rail station car parks.

For a camera charge that got the times wrong, joined two visits into one, or misread your plate. Demands the operator's full camera records.

For a charge that is out of all proportion to any real loss. Honest note: most standard charges are lawful, so use this alongside a stronger ground, not instead of one.

For a charge issued only minutes after your time ran out. Most car parks must allow a grace period. Not for you if you hadn't paid or had no permit.

For when you weren't driving, or weren't the keeper at the time. Explains what the operator has to prove, and confirms you don't have to name the driver.

For when you paid but typed your registration wrongly. Small slips and bigger mistakes are treated differently; this covers both, so you don't need to work out which applies.

For a Notice to Keeper you think arrived late. A date checker, the letter, and a plain guide to proving when it arrived. It will tell you honestly if yours was in time.

For when you doubt the operator has the landowner's permission to issue charges. Makes them prove that authority before anything else happens.

For a notice made to look official, using words like "fine" or "Penalty Charge Notice", or missing information it must give you. Built on the current Code of Practice.

For a charge when you had paid, at the machine or by app such as RingGo or PayByPhone. Puts your proof first and makes the operator check its own records.

For a Notice to Keeper that leaves out wording the law requires. A notice missing it can't make the keeper liable. The letter shows you exactly what to look for.

For a Notice to Keeper that reached you later than the law allows, whether or not you had a windscreen ticket first. If it was late, the keeper can't be made to pay.

Your first appeal to a private parking company. Covers the grounds that apply to most charges. Start here if you're not sure which letter fits.

For when the sign was there but a driver could not see it: blocked by another vehicle, behind foliage, facing the wrong way, or mounted too high. Photographs from the driver's seat do the work.

For a car park where the signs were missing, hidden, too small to read, or didn't show the charge before you parked. Built on the current Code of Practice.

For a charge at a Tube, Overground, DLR, Elizabeth line, Tramlink, Tyne and Wear Metro or Nottingham tram car park. Challenges keeper liability. Not for National Rail stations.

For a TfL bus lane penalty where the signs were wrong, the lane wasn't in force, your vehicle was allowed, or you only crossed it briefly.

For a Congestion Charge penalty where you paid, were entitled to a discount, or weren't in the zone.

For a TfL box junction or banned turn penalty. Built on the London rules, which differ from the rest of England, and on what a box junction ban actually covers.

For a TfL red route penalty where the signs or markings were wrong, you were allowed to stop, or the camera evidence doesn't show what TfL says.

For appealing to the independent adjudicator after TfL has turned you down, including if you've missed the deadline.

The general ULEZ challenge, if you're not sure which letter fits. Covers every ground TfL must consider, and keeps honest mistakes separate because they're handled differently.

For a ULEZ penalty when you paid the right charge for the right day. Not for a payment on the wrong plate or date: that's a different letter.

For a ULEZ penalty caused by someone else using your number plate. Shows you the evidence TfL needs before it will accept it.

Everything for a ULEZ penalty caused by a cloned plate: what to do and when, the evidence, the letter, and the appeal.

For a ULEZ penalty on a vehicle in the disabled or disabled passenger tax class. Check your V5C first: getting PIP or DLA isn't enough on its own.

For hire companies passing a ULEZ penalty on to the customer who hired the vehicle.

For a ULEZ or LEZ penalty on an overseas-registered vehicle where the amount is wrong or has fees or exchange charges added.

For a ULEZ penalty after you paid but got the plate or date wrong. Asks TfL to use its discretion, which is the right route for this.

For a ULEZ penalty that has reached the county court when you never received the notice or TfL never answered you. Strict time limit.

For a ULEZ penalty when your vehicle actually meets the emissions standard. Sets out your vehicle's evidence clearly and answers TfL's usual reasons for refusing.

Everything for a ULEZ penalty when your vehicle meets the standard: the evidence to get, the letter, TfL's likely replies, and the appeal.

For a ULEZ penalty when your vehicle was taken or used without your permission. Not for a family member who normally has permission.

For a ULEZ penalty sent to you when you'd sold the vehicle, hadn't yet bought it, or never owned it.

For a council Notice to Owner, after your first challenge was refused. Protects your right to appeal to the independent tribunal.

For a council parking ticket, before your discount runs out. Challenges it while you can still pay the lower amount if they say no.

Everything for appealing a Clean Air Zone penalty to the Traffic Penalty Tribunal, including if you're late, and a fallback if the appeal itself fails.

For a Clean Air Zone penalty when you paid the right charge for the right day.

For a Clean Air Zone penalty where your circumstances were exceptional. Outside London the council must consider this, and must cancel if it agrees.

For hire companies passing a Clean Air Zone penalty on to the customer who hired the vehicle.

For when a Clean Air Zone council says your challenge was too late, or your deadline is close. Checks how the dates were really worked out.

For a Clean Air Zone penalty where the amount is wrong for the stage you're at.

For a Clean Air Zone penalty outside London where the council didn't follow the rules on notices, dates or signs. A ground most online letters miss.

For a Clean Air Zone penalty outside London when your vehicle meets the standard your zone uses.

For a Clean Air Zone penalty when your vehicle was taken or used without your permission. Not for a family member who normally has permission.

For a Clean Air Zone penalty sent to you when you'd sold the vehicle, hadn't yet bought it, or never owned it.