Towards a classification of the Central London congestion charge as a tax

The recent and ongoing diplomatic dispute surrounding the classification of the Central London Congestion Charge,
according to the Vienna Convention on Diplomatic Relations, highlights the uncertainty that surrounds the definitional
delineation of payments as taxes on the one hand and user charges on the other. By reference to the most frequently cited
criteria of a user charge, this article argues that the Central London Congestion Charge is not a user charge and that it is
more accurately described as a tax, both generally and for the purposes of the Vienna Convention on Diplomatic Relations.
Moreover, this article argues that where there is either disagreement or uncertainty as to the precise level of service provided
by a government scheme, reference should be made to the financial accounts of that scheme. Where there is evidence that
the scheme generates a profit over and above a reasonable rate of return, the payment should be classified as a tax.