Question to the Department for Work and Pensions:

To ask the Secretary of State for Work and Pensions, what recent assessment he has made of the accuracy of the payment calculation approach used by the Child Maintenance Service.

The Department of Work and Pensions assures the accuracy of Child Maintenance payment calculations. As part of its Quality Framework, the measurement carried out by the Department is then independently assured by the National Audit Office.

Information on calculation accuracy is published annually in the Child Maintenance Service Client Funds Accounts, which show that since 2020 the CMS has consistently achieved an assessment accuracy rate exceeding the benchmark of 99%.

Around 90 per cent of Child Maintenance calculations are based on verified HMRC earnings data and DWP benefit records, reducing the risk of income mis‑declaration, supporting timely and reliable assessments. Calculations use the most recent HMRC tax year available, are automatically reviewed annually, and may be reassessed at any time where income changes by 25 per cent or more. Statutory rates reflect income, number of children and shared care arrangements, with a flat rate protecting those on the lowest incomes.

The Department regularly review the calculation methodology to ensure it remains fair, accurate and supports compliance.