Law in the United Kingdom

Firstly, I should point out that we are not lawyers and you should check for yourself before depending on this information.

If you are using straight vegetable oil as a fuel, or producing it for others to use as a fuel, you should read this HMRC brief:
http://www.hmrc.gov.uk/briefs/excise-duty/brief4307.htm

If you use/produce less than 2500 litres of vegetable oil per year, then you should not need to register with HMRC or pay any duty on the oil, but you will need to keep some records: You should record the date of production and quantity produced in litres.

Larger users/producers will need to "make entry" by sending in a form EX103. You will need to keep records and pay their duty every month or quarter using form HO930. It is not clear to me whether larger producers should be paying the rate of tax for sulphur-free diesel or the reduced rate for biodiesel. HMRC seem to think you should pay the higher rate, but most people seem to believe that the lower rate applies. The answer seems to boil down to a simple chemistry question about the ester content of vegetable oil, but I have not yet seen a convincing answer either way. Before 30th June, this procedure applied to all users of vegetable oil as a fuel, so I made entry and paid duty on the fuel I was using. Because of the uncertainty, I paid the higher rate of 48.35p per litre, rather than the biodiesel rate of 28.35p per litre. Making entry is free and relatively fast - It took just over a week.

If you are using waste vegetable oil, all of the above applies, plus you will need to check that you can legally use waste oil.

If you are dealing with waste oil from other people or businesses located in England or Wales, you must register with the Environment Agency. Their website is http://www.environment-agency.gov.uk/. Registering involves a fairly long form and currently costs £149 for the first three years, plus an extra £5 if you want a plastic card. The process takes about two months. Once you are registered, you can collect and use waste oil as long as you keep records and dispose of the waste in an environmentally friendly manner.

If you are dealing with waste oil in Scotland, you need to register with the Scottish Environment Protection Agency. Their website is http//www.sepa.org.uk. In Northern Ireland, the appropriate body is the Hazardous Waste/TFS Section of the Land and Resource Management Unit, Environment and Heritage Service. Their phone number is 028 90569313.

If you are using your own waste vegetable oil, rather than collecting waste from other people, you may not need to register as a waste carrier, but please check with the appropriate Agency.