"Challenge", "appeal", "representations": councils use the words loosely, but the law has two distinct steps, and which one you are at depends on how you got the PCN.
Informal challenge: PCNs left on the car
When a civil enforcement officer fixes a PCN to the windscreen or hands it to you, you can write to the council straight away. This is the informal challenge. The PCN itself must tell you that representations received before a Notice to Owner is sent will be considered (SI 2022/576, reg 3(1)).
If the council rejects an informal challenge, you have not lost your formal rights. If the PCN stays unpaid for 28 days the council can send a Notice to Owner, and you can then make formal representations, even if they repeat what you said before.
Formal representations: Notice to Owner or postal PCN
Formal representations are made against a Notice to Owner, or against a PCN sent by post (camera PCNs, and some where the officer was prevented from issuing it). They must be made in the form the council sets, within 28 days of the notice being served, and can rely on the statutory grounds, compelling reasons, or both (reg 5).
Formal representations carry two protections the informal stage does not: the council must send a written decision, and in England it must do so within 56 days of receiving them or they are treated as accepted. If it rejects them, the Notice of Rejection opens the door to a free tribunal appeal.
Camera PCNs skip the informal stage
A bus lane, bus gate, box junction or other camera PCN arrives by post and is itself the formal notice. There is no Notice to Owner, so your first letter is your formal representations. Do not wait for another notice.
Which letter do I need?
- PCN on your windscreen, nothing else yet: informal challenge.
- Notice to Owner, or any PCN sent by post: formal representations.
- Notice of Rejection: tribunal appeal (TPT or London Tribunals).