DRIVERS have discovered a massive loophole to avoid paying a £12.50 road charge.
The levy has been controversial since its inception four years ago and has met with significant resistance from angry motorists.
Londoners have been rebelling against the ULEZ charge, especially so after the zone expanded in August.
This has included the now-infamous 'Blade Runners' sabotaging enforcement cameras in a spate of attacks.
However, some have found a more peaceful (and legal) form of resistance by scouting out some gaps in the rules that govern ULEZ.
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All the regulations can be found on the Transport for London (TfL) website and some eagle-eyed readers have spied some interesting exceptions.
For example, military vehicles, some forms of farming equipment and even "certain types of mobile cranes" are all exempt.
Indeed, this particular loophole was tested out when a group of anti-ULEZ campaigners drove a tank through central London earlier this year.
However, there are some broader categories which can qualify you for an exemption.
If your vehicle is registered as owned by a disabled driver or as a "disabled passenger vehicle", there is a "grace period" of no charges until October 24 2027.
A similar period lasts until the next day for those claiming certain disability benefits, including PIP, War Pensioners' Mobility Supplement or ADP.
And if you are incapacitated by a medical emergency or long-term illness that makes it difficult to walk, you must still make payments but these can be claimed back after your journey.
Possibly the widest category, though, is the exception for "historic vehicles", which are permanently free of charge.
These are defined as any vehicle manufactured more than 40 years ago on a rolling basis - the current cutoff is 1983, moving to 1984 next year.
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That means that by 2050, any car manufactured up to 2010 will be exempt.
Likewise, "showman's vehicles" being used for performances, carrying performance equipment or displaying animals are not subject to the charge.
And, of course, if your motor complies with ULEZ standards, you don't need to pay at all.
This means you only have to worry about these loopholes if, as a rule of thumb, you have a petrol car made before 2005, a diesel made before 2015 or a motorcycle made before 2007.
The full list of exemption requirements, including exact emissions allowances for newer cars, can be found on TfL's website.