Brief Description: This paper tells how HM Revenue and Customs borrowed from theories of behavioural psychology, to take a more positive approach in their communications. The HM Revenue and Custom’s Self Assessment campaign, with the strapline, ‘tax doesn’t have to be taxing’, has resulted in record numbers of taxpayers filing in their tax returns on time. Targets for internet filing have been shattered three years running, and take-up now stands at over 20 times the level prior to launch. There has also been a dramatic uplift in the sense that HM Revenue and Customs is changing for the better, and that Self Assessment is getting easier. Altogether, the campaign has generated savings of £547m on a total spend of £22.5m: an ROI of £24.31 for every £1 invested; ---(TAGS)--- Full Title: Self assessment - How a change in advertising direction proved that tax doesn't have to be taxing; Number: 2006/18; Brand: COI - HM Revenue & Customs - Self Assessment; Client: HM Revenue and Customs; Product Category: Government Departments (Public service information campaigns); Agency: Miles Calcraft Briginshaw Duffy; Author: Andy Nairn; Prize Winners: Bronze (Adworks ref: Advertising Works 15 Summary)