Railway companies carried mail for the Post Office and parcels for themselves and the Post Office. They could not convey single letters. This changed on 1 February 1891 when the Railway Letter Post began. Provided the normal postage was paid and a fee of 2d to the railway company (paid by private company stamps of a standard design) letters could be accepted at any railway station for onward transmission by train and then in the normal post. This did not apply to letters over one ounce or to mail going abroad. Mail could also be sent to a station and kept “to be called for” over a period of seven days.
Designs were provided by De La Rue for special stamps for this service in February and April 1890. These bore a 3d denomination for the entire cost of sending a letter in this fashion. Difficulties in dividing the revenue meant that this was not adopted and separate railway company labels for 2d were introduced instead.