All public sector organisations rely to varying degrees on postal services, costing nearly £650 million annually of which £250 million is spent by central government departments. The two biggest spenders are the Department for Work and Pensions and HM Revenue and Customs which account for over half this amount, with ten organisations accounting for 95 per cent of the total. Despite the growth in the use of internet and email, at least for the foreseeable future conventional mail will remain essential to the way public bodies communicate with the public. This NAO report examines how public sector organisations can become more effective in their procurement and management of postal services, and identifies six main areas where further improvements can be made in order to realise an estimated £31 million a year in savings by 2008-09. Two accompanying documents are available separately: case studies which examine the use of postal services in five organisations (HCP 946-II, ISBN 0102937354); and a guide which sets out examples of good practice across public and private sectors (HCP 946-III, ISBN 0102937362).