The Inland Revenue Staff Federation (IRSF) was a trade union in the United Kingdom.

At that time clerks were hired by surveyors of taxes, they were usually employed on a temporary basis, paid low wages and denied sick leave, holidays or promotion.

Its Assistant Secretary from 1936 until World War II was future Prime Minister of the United Kingdom James Callaghan.

The roots of the Federation go back to 1883 and the founding of the London Association of Assessors and Collectors, but only after 1937 did it fully represent all staff grades at the Inland Revenue.

At the 1986 Jubilee Celebration, the IRSF was described as a modern efficient organisation, with a high profile in the trade union movement, with a membership of 55,000.