Experts have warned that motorists could face fines of up to £200 for a common habit. Drivers in the UK could also receive penalty points on their licence for this seemingly innocent gesture.
Many drivers believe they’re being polite when they flash their headlights to alert others about speed cameras, yield at junctions, or acknowledge fellow drivers. Nevertheless, these flashes actually breach Highway Code Rule 110 and could lead to fines reaching £200 plus penalty points.
More worryingly still, drivers who flash their lights to alert others about police presence could face severe penalties of up to £1,000 for obstructing police operations.
Highway Code Rule 110 specifies that motorists should “only flash your headlights to let other road users know that you are there.”
It states: “Do not flash your headlights to convey any other message or intimidate other road users.” This means practically every typical use of headlight flashing technically violates the code, including alerting other motorists to speed cameras, yielding at junctions, signalling appreciation, or showing annoyance.
The sanctions vary depending on precisely why drivers flashed their lights, establishing a bewildering dual system that most road users don’t realise exists.
For standard misuse, such as yielding or expressing gratitude, drivers risk fines between £100 and £200 alongside three to six penalty points for careless driving.
However, sanctions become considerably harsher for alerting others about police speed traps.
This can be charged as “wilfully obstructing a constable” under Section 89 of the Police Act 1996, carrying a maximum penalty of £1,000.
Tom Riley, a car finance expert and owner of Simple PCP Claims, explains: “Most drivers flash their lights with good intentions, thinking they’re being helpful.
“But the law is crystal clear, you can only flash your headlights to alert others to your presence. Anything else could technically land you in hot water.”
These regulations originate from the Road Vehicles Lighting Regulations 1989. Although breaches of the Highway Code aren’t directly criminal, police can issue penalties when misuse creates danger or hinders law enforcement.
The Crown Prosecution Service specifically cites “giving a warning to other motorists of a police speed trap ahead” as an example of obstructing police duties, making it clear this common practice is actively targeted by authorities.
While prosecution for everyday “polite” flashing remains relatively rare, the legal framework exists to catch drivers who step outside legally acceptable bounds. Traffic officers are particularly vigilant about drivers warning others of speed cameras.
The confusion comes because headlight flashing has become popular in British driving culture. Many drivers assume it’s perfectly legal, having learned these habits during lessons or from experienced drivers.
Tom added: “The £200 fine might not sound enormous, but add penalty points and you’re looking at a serious hit to your driving record.
“For drivers who warn others about speed traps, that £1,000 maximum penalty could be financially devastating. The safest approach is simple, only flash when you genuinely need to alert someone to your presence.”