Coal-tax posts are marker posts, now numbering about 210 but originally about 280 in number, erected in the 1860s and forming an irregular loop between 12 and 18 miles from London, England, to mark the points where taxes on coal were due to the Corporation of London.
Coal imported into the City of London had been taxed since mediaeval times and, as it was originally all brought by sea to riverside wharfs, the collection of the duties was relatively easy. The City is a small (one square mile) but influential part of London. The Port of London, within which the duties were payable, stretched far beyond the boundaries of the City, all the way along the Thames from Yantlet Creek (downstream from Gravesend) to Staines.
By the 19th century, however, there was increasing trade by canal and rail, and various Acts of Parliament extended the catchment area to include these new modes of transport. In 1845 the boundary was set at a radius of 20 miles from the General Post Office, London, from Langley in the west to Gravesend in the east and from Ware in the north to Redhill in the south. In 1851 an Act permitted the erection of boundary markers to indicate where this boundary lay; and about 50 markers, inscribed with a reference to the Act, were erected.
In 1861 a further Act — the London Coal and Wine Duties Continuance Act 1861 — was passed, reducing the area to that of the Metropolitan Police District plus the City of London. This stretched from Colnbrook in the west to Crayford Ness, at the mouth of the River Darent, in the east, and from Wormley, Hertfordshire in the north to Banstead Heath, Surrey in the south. New marker posts (about 280) were erected to show the boundary within which the duty was payable. These again cite the Act by regnal year and chapter number, i.e. 24 & 25 VICT CAP 42. In some cases, notably on railways and canals, markers made for earlier acts were reused on the new boundary. Most (over 200) of these posts survive. Although the title of the Act refers to wine duties, these were collected only in the Port of London: the boundary marks have no connection with the wine duties and it is incorrect to call them "coal and wine duty posts".
The purpose of the posts was to give notice of where the boundary ran so that no-one could claim ignorance of liability to pay the duties. However, in general, duties were not actually collected on the boundary. The one known exception was the Grand Junction Canal: originally customs officers collected the duties at Grove Park, Hertfordshire. After the boundary was changed in 1861 a permanent house for the collector was built at Stockers Lock near Rickmansworth. In other cases the railway and canal companies or local coal merchants calculated the sums due and paid the money to the Corporation. The railway companies were initially allowed some coal free of duty for their engines.
The coal duties had always been unpopular and were the subject of attacks by pamphleteers (for example Firth in 1887) etc. throughout their life. Objection was taken to a tax on a basic necessity and the anomaly of a tax in London which did not apply to the rest of the country. The greater anomaly was that the area of collection – the Metropolitan Police District – was so much larger than the area in which they were spent: the Metropolitan Board of Works covered much the same area as its successor the London County Council. With the growth of the outer suburbs, their residents resented paying a tax which had very little direct benefit for them. This is why in 1868 Parliament decided that the duties were to be used to free from toll the bridges in outer London mentioned above.
In the 1880s the City and the MBW wanted the duties to continue, in the face of growing opposition from the public and national politicians, but when the MBW was replaced by the London County Council in 1889, the new council declined to support renewal. An act was passed in that year abolishing the duties, the last of which was collected in 1890. The abolition was opposed with some underhand tactics: a parliamentary select committee sitting in 1887 found that signatures on a petition in support of keeping the tax had been forged.
The posts thus represent the final phase of the duties in the face of growing opposition. They had been collected for over 300 years but within 30 years of the posts going up were abolished.