A central office (or Intergroup) is an A.A. service office that involves partnership among groups in a community — just as A.A. groups themselves are partnerships of individuals.
A central office is established to carry out certain functions common to all the groups — functions which are best handled by a centralized office — and it is usually maintained, supervised, and supported by these groups in their general interest.
It exists to aid the groups in their common purpose of carrying the A.A message to the alcoholic who still suffers.
Reprinted from: A.A Guidelines Central or Intergroup Offices, Permission of: A.A. World Services, Inc.