Vessy was admitted as a freeman of Exeter on 17 Jan. 1412, paying a fee of 20s. for the privilege. From then until his death he played an active role in the government of the city, appearing as an elector of local officials on as many as 13 occasions, and discharging tasks of administration almost continuously from 1415 until his death. His principal trading concern was fish, but his other description as ‘chapman’ suggests that he also dealt in a wide variety of commodities. Many of his dealings took place in London. It was as a ‘fishmonger of London’ that in October 1412 he procured a pardon of outlawry for failing to present himself to answer for a debt of 50s. owing to two vintners of the City, and in 1420, after a short period of imprisonment in the Fleet, he was again pardoned his outlawry in the London court of husting following proceedings over a debt of 25 marks brought by John Payn, a stockfishmonger. Other creditors of Vessy’s included a tallow chandler and a bladesmith, who also traded in the capital. No doubt his mercantile interests made him a willing candidate for election to Parliaments summoned to Westminster.
In October 1423 Vessy not only attested the parliamentary indenture of election of the knights of the shire in the county court held at Exeter castle, but also offered sureties for the appearance in the Commons of John Shaplegh II, one of the citizens—elect for Exeter. Apart from his house in the city he also held half a knight’s fee in Throwleigh, several miles away, although how he had acquired this remains unclear.