go through channels
Use the correct procedure, especially in a hierarchy or bureaucracy. For example, You'll have to go through channels for approval of this expenditure. This term uses channel in the sense of “a conduit.” [Mid-1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.