Question to the HM Treasury:

To ask Mr Chancellor of the Exchequer, what changes have been made to the methodology for assessing compliance yield for tax collection in the last 10 years.

It is important that HMRC's methodology for assessing the effects of its compliance activities reflect the full range of impacts of its activities on customer compliance. Both to provide accountability for its overall performance and to manage its business and the performance of its compliance teams on a day-to-day basis. HMRC periodically refines its methodology for compliance yield to reflect the latest evidence. This is consistent with recommendations from the NAO and PAC.

Changes at the start of this Government were implemented to better assess the total impact of HMRC's work. Some reduced the revenue HMRC could score, while others recognised that HMRC were achieving a greater impact on future taxpayer behaviour than they had previously assumed.

Key changes to scoring rules at the start of the 2010 Spending Review period were:

1. Ensuring reported performance better reflects the amount of revenue that HMRC can expect to receive

2. Recognising the revenue effects of work against criminals

3. Refining our methodology to reflect our latest understanding of the effects of our interventions on customers' behaviour in the future.

Further information on HMRC's compliance methodology will be set out in its Annual Report, which will be published in due course.