Question to the Department for Work and Pensions:

To ask the Secretary of State for Work and Pensions, what assessment he has made of the extent to which administrative errors by the Child Maintenance Service contribute to the creation of incorrect arrears; and what steps his Department is taking to rectify such cases.

The Child Maintenance Service (CMS) is committed to providing timely, transparent, and accurate information to parents. To support this, CMS uses proportionate controls to ensure calculation accuracy, including verified income from HMRC and Child Benefit systems, dedicated verification processes, and a three tier quality framework. These measures help minimise administrative and calculation errors that could otherwise contribute to incorrect arrears being created.

Where CMS identifies—either through its internal checks or following a parent’s challenge—that a single accidental error relating to the maintenance calculation has occurred, it can apply a correction without requiring a full Mandatory Reconsideration (MR), provided the challenge is raised within legislative timescales. The CMS also operates a liability schedule which acts as the authoritative record of assessed liability, payments received, and arrears, ensuring over‑ and under‑payments are correctly reconciled.

All calculation decisions may be challenged through the MR process, which allows a parent to request a review before appealing to His Majesty’s Courts and Tribunals Service. During MR, CMS reassesses the decision and considers any new information; where an error is confirmed, the decision is revised accordingly.

Through the Service Modernisation Programme, the Child Maintenance Service (CMS) has strengthened accuracy and communication by introducing enhanced digital tools, clearer written communications, expanded use of SMS and email, and greater self‑service functionality. These improvements, including automated processing of simple case updates through My Child Maintenance Case (MCMC), enable parents to access and update case information 24/7, improve accuracy, reduce administrative errors, and speed up changes.

The Department rigorously monitors accuracy and continues to meet the National Audit Office (NAO) monetary error target of under 1%, ensuring robust oversight of error rates and arrears calculations.