The National Audit Office has started an investigation into HM Revenue and Customs' use of Home Office travel data to check child benefit claims. The probe covers the design, governance, implementation, and risk management of the system.

HMRC suspended child benefit payments for 23,794 families from July to October. Parents received letters about past holidays, some dating back three years, where Home Office records lacked evidence of return trips to the UK.

As of 31 December, more than 17,000 families proved eligible to continue receiving payments. Only 1,019 cases involved incorrect claims. Thousands of cases remain unresolved.

Some Northern Ireland families lost benefits after entering the UK through Dublin airport. Others faced payment freezes due to missing Home Office return records.

Andrew Snowden MP welcomed the NAO investigation. He highlighted a lack of transparency on the policy design, data used, and reasons for erroneous suspensions. Snowden stressed the need to establish who knew what and when to prevent repeats.

Internal HMRC documents from mid-November stated the Home Office data exchange worked as expected. Officials anticipated 64% of cases would prove ineligible, but by late November 63% were legitimate, rising to 71% by December end. HMRC has issued no further figures.

The documents justified initial payment suspensions to prompt eligibility confirmations, a practice now dropped. John-Paul Marks, HMRC's first permanent secretary and chief executive, wrote to the House of Commons treasury select committee about a revised approach. He noted discussions with the NAO and plans for an oversight group to monitor future use of travel data.