The National Association of Head Teachers says it now receives 600 calls a week from members seeking advice on professional matters, such as staffing, significantly up on previous years.
In 2000, regional officers handled 1,932 cases where members' employment was at risk - up 8 per cent on the previous year. And calls to the association's pensions and salaries experts have nearly doubled in three years, from around 9,000 in 1998 to just over 17,000 last year.
"It does seem that our members are under increasing pressure," said Mike Turnbull, executive director.
Kerry George, NAHT's assistant secretary for salaries, pensions and conditions of service, said calls were running at 1,800 a month in July 2000, compared to only 700 in 1996.
Particular events, such as last summer's court challenge to threshold payments, brought by the National Union of Teachers, contributed to peaks in demand. But the overall trnd was upwards, she said.
The increasing demand for services is straining the association's resources, given its stable membership of just over 30,000. Last week, its annual conference agreed to increase membership fees for the first time in three years, in part to meet demand for services, and the association has taken on additional regional and headquarters staff.
Headteachers' fees will rise from pound;200 to pound;210. However, deputy head charges have been frozen at pound;200, and a lower rate of pound;170 introduced for assistant heads.
The smaller Secondary Heads' Association says calls to its helpline are up from an average 30 a day two years ago to 40 and sometimes 50 a day now. Assistant general secretary Bob Carstairs said that represented a significant increase in calls, even set against rising membership.
Subjects raised ranged from the General Teaching Council's membership fee to implementing the latest Department for Education and Employment initiative.
"The initiatives pile up. Most people cope with it, but it is clear that some are having to work a lot harder than seven years ago."