He was also ordered to examine Sir Thomas Craig's work Jus Feudale, with a view to its publication.
He was employed in 1639 in regulating the fees of writers to the signet and others, and parliament adopted the scales which he laid down.
The matter was referred to the privy council, and as Fletcher retained his seat the charge was presumably disproved.
On the question whether conditions should be obtained from the English army on behalf of Charles I, he was one of the four who voted against abandoning the king, and was removed in 1649 from his offices of judge and commissioner of the exchequer, on account of his accession to "the engagement", for the carrying on of which he had subscribed in the previous year £8,500 (Scots), repaid by order of parliament in 1662 after his death to his son Robert.
Fletcher married a daughter of Peter Hay of Kirkland of Megginch, brother to George Hay, 1st Earl of Kinnoull, by whom he had two sons: Robert, afterwards knighted, who was father of Andrew Fletcher of Saltoun, and Henry, ancestor of the Irish branch of the family.