The acts in which Hay performed the schoolmaster sketch became known as "The Fourth Form at St. Michael's". Hay toured with the act and appeared in the United States, Canada, Australia and South Africa. His wife, Gladys, often played a schoolboy or the character Harbottle in his sketches. The Harbottle character was one of the most popular in Hay's act, a dim-witted, nearly deaf old man who is still in school because he's so backward. The character later featured in Hay's films portrayed by Moore Marriott. In a 1976 interview, Val Guest who served as a screenwriter for many of Hay's films, recalled transposing Harbottle from school into other everyday situations. He famously performed the schoolmaster routine at the 1925 Royal Command Performance before King George V and Queen Mary. This was widely regarded as one of his most famous performances.
Comedians who have cited Hay as an influence include Ken Dodd, Eric Morecambe, Tommy Cooper, Harry Worth, Harry Enfield, Jimmy Perry and David Croft. Ronnie Barker also cited Hay as an influence, and in 1976 hosted a documentary on BBC Radio that discussed Hay's life and career.