In 1378 Waltham held a brief position as rector at the Parish Church of St. Mary, South Kelsey in the Diocese of Lincoln, from February to May of that year, being presented to the church of in the king's gift. In the following year, Waltham was offered the post of canon at the Collegiate Church of St Mary and St Cuthbert, Chester-le-Street in the Diocese of Durham, but instead he took up a post at the church of Grendon in the diocese of Lincoln on 17 June 1379. Three months later, on 18 September, Waltham was nominated to a canonry at St Andrew's Collegiate Church in Bishop Auckland, County Durham. He was presented by King Richard II as rector of the Church of St Peter, Great Berkhamsted on 27 December 1379, a post which he held for under two years before he resigned on 22 April 1381. Waltham held the office of Archdeacon of Richmond from 1385 to 1388.