He matriculated at The Queen's College, Oxford, on 27 October 1778, and was called to the bar by the society of the Inner Temple in the Hilary term of 1783.
[2] For some years Tomlins was editor of the St. James's Chronicle, a daily newspaper, and on 30 May 1801 he was appointed counsel to the chief secretary for Ireland.
In the same year he became parliamentary counsel to the Chancellor of the Exchequer for Ireland, a post which he retained until the union of the British and Irish treasuries in 1816.
He was knighted at Wanstead House on 29 June 1814, on the recommendation of the Duke of Wellington, and in 1818 was appointed assistant counsel to the treasury.
[2] Jointly with his sister Elizabeth Sophia Tomlins he published a collection of short poems, Tributes of Affection by a Lady and her Brother, in 1797.