As a younger son excluded from his patrimony by primogeniture, he was expected to make his own fortune and left Clopton for the City of London at an early age, where he was apprenticed in 1457 to the mercer John Roo, and was admitted to the Worshipful Company of Mercers in 1464. He served as Warden of the Company three times, in 1479, 1484 and 1488. On 15 October 1485 he was chosen as Alderman for Dowgate ward. In 1486 he was elected Sheriff of London during Sir Henry Colet's term as mayor, and was himself chosen Lord Mayor of London in 1491. By 1495 he was living in Bread Street. Although some biographers have stated that he was knighted, this does not appear to have been the case as he described himself in his will merely as "citizen, mercer and alderman".