For the salary year beginning April 2008, unpromoted teachers in Scotland earned from £20,427 for a Probationer, up to £32,583 after 6 years teaching, but could then go on to earn up to £39,942 as they complete the modules to earn Chartered Teacher Status (requiring at least 6 years at up to two modules per year.) Promotion to Principal Teacher positions attracts a salary of between £34,566 and £44,616; Deputy Head, and Head teachers earn from £40,290 to £78,642. Teachers in Scotland can be registered members of trade unions with the main ones being the Educational Institute of Scotland and the Scottish Secondary Teachers' Association.