With millions unaware that tax discs are being scrapped and the rules changed, here are a dozen other regulations you might never even have known existed.
Tax disc laws are being radically overhauled from the start of October – but driver surveys suggest millions of people are unaware and could face huge fines as a result.
But these are far from the only laws that it seems many people could be about to break without realising.
More than a year on from the introduction of rules banning hogging the middle lane of the motorway, new research reported by the Mirror shows that barely 50 per cent of drivers know about the potential fines and point penalties involved.
Other rules of the road are more commonly known and taught but selectively ignored. You wouldn’t think it if you have ever been in traffic in a busy town or city, but the police say car horns should strictly only be used to warn of immediate danger.
Away from the road, recent compilations of the UK’s “most ludicrous” laws have often looked into the distant past for bizarre legislation – often ignoring the fact that it is no longer in force.
Yet as recently as 1986 a law was passed banning the “handling of salmon in suspicious circumstances”.
According to the official Transport for London Railway Byelaws, sanctioned by the secretary of state in 2011, it is illegal to jump a queue in a Tube station.
And though it is unclear whether the law has been enforced yet, a provision of the 2005 Clean Neighbourhoods and Environment Act makes it an offence to activate your burglar alarm without first nominating a “key-holder” who can switch it off in your absence.
Never mind the urban myths about dying in Westminster or eating mince pies on Christmas Day – click through the gallery for 13 laws you may genuinely be breaking without even realising it.
13 laws you didn't know you were breaking
13 laws you didn't know you were breaking
1/13 1. Salmon handling
It's illegal to handle salmon in suspicious circumstances, according to the Salmon Act of 1986. While this is clearly related to selling fish gained through illicit means, the law is oddly broad in its wording
Thomas D Mangelsen/The Masters of Nature Photography/Natural History Museum
2/13 2. Unattended alarms
It is an offence under a provision of the Clean Neighbourhoods and Environment Act 2005 to leave your property with a burglar alarm activated unless you have named a “key-holder” responsible for shutting it off if you are away
20th Century Fox
3/13 3. Queue jumping
Shoppers queue in the early morning outside Selfridges department store in central London in search of a bargain in the post Christmas Boxing Day sales
4/13 4. Lane hogging
Last year the roads safety minister Stephen Hammond warned that drivers who hogged the middle lane of motorways, drove while using their mobile phones or tailgated other road users faced on the spot fines and three points on their licence
5/13 5. Mat shaking
Many rules brought in by the Metropolitan Police Act 1839 have since been repealed or revised by newer laws. One which hasn’t, however, makes it illegal to beat or shake any carpet rug or mat in any street in the Metropolitan Police District
6/13 6. Washing lines
Also under the Metropolitan Police Act 1839, it is illegal to erect a washing line across any “thoroughfares” in the city
7/13 7. Door knocking
Seen by many as a harmless (if annoying) children’s game, knocking on someone’s door and running away is actually illegal under the 1839 law. It makes it an offence to 'wilfully and wantonly disturb any inhabitant by pulling or ringing any door-bell or knocking at any door without lawful excuse'
8/13 8. Singing in the street
Again under the Metropolitan Police Act 1839, it is illegal to “sing any profane, indecent, or obscene song or ballad” in the street. Bad news for stag parties and football fans, then
9/13 9. Being drunk in the pub
This often-cited law strictly-speaking actually makes it illegal for the owner or manager of a licensed premises to “permit drunkenness or other disorderly conduct” – meaning it is not an offence to be that drunk person yourself. It is, however, illegal to buy a drink for someone who is drunk
10/13 10. Bad references
It is sometimes said that it is illegal for an employer to give a bad reference – meaning many will simply decline to provide one. Though this isn’t strictly the case, a false bad reference is considered libellous – so employers need to be prepared to back up their words in court
11/13 11. TV licences
The law states that you don’t need a TV licence if you use your TV only to watch DVDs, play video games or use ‘catch-up’ services. But if you stream anything live at the time it is broadcast – even if it is on a laptop and you don’t own a TV at all – you’re breaking the law
12/13 12. Horn misuse
The police are very clear on this –according to their explanation of the rules, “a horn should only be used when warning someone of danger, not to indicate your annoyance at a manner of driving”
13/13 13. Tax discs
As of 1 October, it will be illegal to 'transfer' car tax when buying a second-hand vehicle. Anyone who fails to immediately tell the DVLA when they sell their car could face fines of up to £1,000