Red diesel is simply diesel which is dyed to indicate it is rebated and hence subject to less fuel duty and VAT than normal (white) diesel. Currently, most non-road machinery is capable of being powered by red diesel, which is significantly cheaper than white diesel, but as a result of the government’s climate change policy the exemptions are reformed such that they will only apply to very specific uses such as for agriculture or for non-commercial heating. This means that any business outside of these specific sectors using red diesel will need to deplete stocks and prepare for an increased fuel bill from 1 April 2022. Those no longer able to use red diesel after 1 April 2022 are (but not limited to):
A minor point, but red diesel in vehicles added before 1 April 2022 will be capable of being used up after that date provided it qualified before 1 April 2022. Any in storage at 1 April 2022 should be disposed of or transferred. Tanks do not need to be flushed out after 1 April 2022.