The stakes are high when engaging an external consultant to undertake Organisation Development (OD) work. Not only must an organisation bear the cost of consultancy fees, but the cost of poor advice or expertise could ultimately be much greater than this. With The National Audit Office report into spending on external consultants across UK central government (Oct 2010) noting that a number of departments had ‘not been acting as intelligent customers’, it’s time to provide internal practitioners with more guidance about how to effectively buy in external OD support.