Free Traffic Legal Advice

I received this PCN on a Saturday despite the restrictions stating it was till 5:30PM on a Friday.

You've not received a PCN for the SYL restriction, but for parking on the pavement, which has been outlawed in London for half a century.

GSV is not very helpful, dating back to 2014 & 2018, however it does show
https://maps.app.goo.gl/MpBkXeUhRmFD19397
https://maps.app.goo.gl/kkviSa2bkTyCYTrh8

marked bays on the pavement and one small sign permitting parking, as well as intensive use of the pavement dor parking which you say vontinues to this day, though the bays (if still there) should be accompanied by signs permitting parking and a traffic order disallowing the ban.

So you may have two grounds for vhallenging the PCN:
a) that parking on the pavement has been permitted since at least 2014 as shown by GSV https://maps.app.goo.gl/DQ1AMxa9sT4nzxzF6

b) even if the ban has not been disallowed, you are entitled to claim 'legitimate expectation' in that the ban has not been enforced for at least 12 years.

You need to do some legwork with a camera to check the current markings situation and to post up a draft challenge here for comment before submitting.


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EDIT:
'I was the only one ticketed' won't wash with either Council or adjudicator.

Until this PCN is resolved, you are on notice that enforcement has commenced, so don't park there again until resolved.

I will visit the street today and take some photos of the bays.

How does this sound ?

Informal challenge :

Dear Sir/Madam.

I believe an offence has not been committed. The vehicle was parked outside the restricted hours ( Mon-Fri 8:30AM - 5:30 PM ). All vehicles during both restricted and unrestricted hours are also expected to park on the pavement closer to the kerb. The part of the pavement where parking is allowed has a significantly noticeable different road surface and also allows for enough remaining space for pedestrians, wheelchair users and prams to be used.
Furthermore, if a vehicle is expected to only park in marked bays on the pavement, the appropriate sign “ P IN MARKED BAYS” should also be placed

Thank you. Informal challenge submitted.