European judges have dashed the hopes of hauliers who thought cheaper fuel was on its way.
In a landmark ruling which will prevent the UK Treasury losing up to £10bn in duty, the European Court of Justice rejected a proposal to allow shoppers to pay duty at the level imposed in the member state where the goods are bought.
Media reports had focused on the purchase of cheap alcohol and cigarettes over the internet but financial experts such as the PKF consultancy thought it could also have applied to fuel.
PKF predicted that hauliers could have ended up paying "up to 70%" less duty if the ruling had gone the other way. Operators with bunkering facilities in the UK would have been able to buy fuel from foreign suppliers and pay the tax in that country rather than at the UK's higher rates.
But the court ruled: "Only products acquired and transported personally by private individuals are exempt from excise duty in the member state of importation."