This study defines an aspect of consultant knowledge that provides credibility without claiming unrealistic status for a field like consulting. Our focus is the “sector knowledge” that consultants accumulate which derives from repeated assignments in the industrial sector in which the client organization resides. This has been under‐researched partly because of an emphasis on knowledge as technique and method. But knowledge configured around the sector enables consultants to play the role of the outside expert and draw on a language and experiences held in common with the client. The paper explores the role of consultants as sector intermediaries through a case study of contemporary management consulting in a UK local authority. We see “the sector” as an alternative type of knowledge formation salient for a client‐centered occupation like consulting. We also explore sector knowledge as a negotiated setting and dispel overly simple notions of know‐how being “brought to” the client. Copyright © 2008 John Wiley & Sons, Ltd.