François's career was considerably accelerated by Jérôme's ministerial favour - he became écrivain principal straightaway on 18 April 1691 at Toulon and on 1 April the following year received his commission as commissaire ordinaire, serving in that role at Toulon then Rochefort, Le Havre and Brest until 1702.
On 1 January 1710, Beauharnois became intendant des classes following the reforms of Pierre Arnoul but he had little time to exercise his new functions - the death of Michel Bégon on 13 March 1710 left the intendances of Rochefort and of the généralité of La Rochelle vacant.