Child Maintenance Service Faces Scrutiny Over 'Crazy' IT Glitches Causing Financial Hardship

The Child Maintenance Service (CMS) is experiencing significant information technology issues that are resulting in parents being overcharged and facing severe financial difficulties, according to a whistleblower.

The caseworker described the IT glitches as "crazy" and estimated that as many as one in five calculations may be incorrect. This situation has led to parents being placed in "desperate straits," with some reporting suicidal thoughts due to the pressure of inflated demands from the government agency. The whistleblower stated that staff are often instructed to tell paying parents to continue payments even when the calculations are known to be wrong and unaffordable.

These accounts align with previous reports, including recordings of CMS staff acknowledging system failures and agency letters attributing incorrect payment demands to system problems. The issues have been compared to the Post Office Horizon scandal.

The whistleblower, who has worked at the CMS for over a year, characterized the system as poorly built. While initial payment amounts are manually calculated and generally accurate, subsequent automated updates or annual reviews can introduce errors. "Sometimes the system can f*** it up," the caseworker said, adding that fixing these mistakes can be substantial. In one instance, the system generated £600 in arrears for a parent who only owed £100.

Regular IT upgrades, referred to as "Sprint," are also cited as a cause of disruption, leading to miscalculations, incorrect correspondence, and access issues for both parents and staff. Minutes from CMS director meetings in 2018, obtained through Freedom of Information requests, also noted concerns about "Sprint."

Further complications arise when the CMS's income data for a paying parent differs from that held by HMRC, which the caseworker believes is a consistent error. Two parents have provided recordings suggesting the system extracted incorrect data from HMRC.

The Daily Mail has reported that relatives of two fathers who died by suicide stated that their struggles with "fictitious" bills from the CMS contributed to their deaths.

Martin Cavanagh of the Public and Commercial Services Union noted that "poor, inflexible IT systems" exacerbate the complexities of the job.

The Department for Work and Pensions (DWP) stated that the CMS undergoes periodic maintenance and upgrades. They maintain that their system is based on the previous tax year's income from HMRC data but allows for adjustments with further information. The DWP asserts that calculations are 99 percent accurate based on the information received, citing an analysis by the National Audit Office. A DWP spokesperson added that while they take shortcomings seriously and are modernizing the service, they have "no evidence of systemic IT faults which affect calculations." They also confirmed that staff are trained to identify and act on mental health risks and that parents have the right to challenge decisions.

One father, Richard Woods, 45, reported being overcharged by more than £20,000 after the CMS incorrectly calculated his income by £63,000 over five years. He was billed £43,000, more than double his actual liability, leading to significant debt. At one point, £3,500 was directly withdrawn from a joint account he shared with his partner while he was unemployed due to the stress of the demands. A recorded CMS call in May 2025 indicated that the inflated income figure was an error the system had pulled from HMRC.

Woods expressed anger over the "wasted years" and the financial losses, noting the stress impacted his children's upbringing. The CMS has the power to seize funds from bank accounts or deduct directly from salaries if payments are not made, even during an appeal process, and can freeze accounts.