Reid commenced work for the law firm Douglas & Dawes and received his qualification as barrister and solicitor in 1862.

[2] By June 1864, Reid had moved to New Zealand and was working as clerk for Charles Button in Invercargill.

[9] In August 1866, Reid's Invercargill household possession were put up for auction as he was leaving Southland permanently.

[17][18] He resigned his position on the County of Westland on 27 April 1871[19] and Conrad Hoos won the resulting by-election.

While he was Solicitor-General, no Attorney-General was in place for the first eighteen months and the last five years, during which periods Reid was thus the Crown's senior law officer.

One of his first tasks in the role was to draft the Abolition of Provinces Act 1875 that abolished the system of provincial governments, and this established him as a constitutional law expert.

[25] Their only daughter, Minnie Ethel Reid, married William Richard Symons (1861–1906) in March 1893; he was the manager of W. and G. Turnbull and Company's shipping department.