Child Maintenance Service Plagued by IT Glitches, Whistleblower Claims

A whistleblower has revealed that the Child Maintenance Service (CMS) is experiencing "crazy" IT glitches that result in parents being overcharged, leading to severe financial hardship and distress. The caseworker, who spoke anonymously, estimated that up to one in five calculations may be incorrect due to these system failures.

These issues have come to light just months after reports indicated that at least two fathers died by suicide after struggling with inflated demands from the agency. The whistleblower stated that the agency receives numerous complaints about incorrect calculations, with some parents expressing suicidal tendencies. Training for staff reportedly includes significant focus on dealing with callers experiencing mental health crises.

Despite staff recognizing that calculations are wrong and that parents cannot afford the amounts demanded, they are allegedly instructed to tell parents to pay regardless. "It happens a lot and is sad, especially when they can’t afford it. All we can do is say to pay it... That’s the policy we are given and have to stick to it," the caseworker said.

Systemic Failures and Escalating Issues

The whistleblower's account aligns with previous evidence suggesting systemic problems within the CMS, including recordings of staff acknowledging the computer system's failures. Letters from the agency have previously blamed system problems for incorrect payment demands, and parents have reported receiving multiple, vastly different payment demands within the same week.

These systemic failures have drawn comparisons to the Post Office Horizon scandal. The caseworker described the CMS IT system as "poorly built" and prone to errors, particularly during automated updates or annual reviews. "Sometimes the system can f*** it up," the caseworker said, adding that correcting these mistakes can be challenging and significant.

Further complicating matters are regular IT upgrades, known as "Sprint," which the whistleblower claims disrupt the system, leading to miscalculations, incorrect correspondence, and access issues for both parents and staff. While the Department for Work and Pensions (DWP) stated in 2018 that such issues were rectified and did not affect calculations, minutes of director meetings from that year obtained by the Mail through Freedom of Information requests do not offer a way to verify this claim, as CMS stopped recording such minutes after 2018.

The system is also intended to cross-reference a paying parent's income with data held by HMRC, but the caseworker reported numerous instances where the CMS held different income figures than HMRC, suggesting a data discrepancy. Recordings from CMS workers have also indicated that the system has extracted incorrect data from HMRC in some cases.

Personal Accounts of Financial Ruin

One father, Richard Woods, 45, reported being overcharged by more than £20,000 over five years due to an income miscalculation by the CMS. The agency billed him £43,000, significantly more than he owed. At one point, when he was unemployed due to stress from the demands, £3,500 was directly withdrawn from a joint account he shared with his partner, money intended for housing.

Woods spent years attempting to resolve the issue, and in a recorded call in May 2025, he was informed that the inflated income figure was "information the system has pulled in" and should not have been applied after a manual check. This error is believed to stem from the system accessing outdated information when linking to HMRC data. Although his income was eventually corrected, Woods expressed anger over the "wasted years" and the financial losses he incurred.

He also highlighted the emotional toll on his children, stating that the stress caused by the CMS's errors affected their upbringing. He argued that by forcing him to overpay, the agency diminished the quality of life he could provide for his children.

The CMS has powers to seize funds directly from bank accounts or deduct wages even while a parent is appealing a decision. The agency can also freeze bank accounts, leaving parents unable to access savings for emergencies.

Official Response and Safeguarding

Martin Cavanagh from the Public and Commercial Services Union stated that "poor, inflexible IT systems" exacerbate an already difficult job for CMS staff. He added, "If the basic IT system is not fit for purpose, then you will always be on that back foot."

The DWP acknowledged that the CMS conducts periodic system maintenance and upgrades. They stated that calculations are based on HMRC data from the last full tax year, but parents can provide additional information to amend the figures. The DWP also cited National Audit Office figures suggesting that calculations are 99% accurate based on the information received.

"More than 4,000 people work across the CMS in eight different locations, managing 810,000 child maintenance arrangements," a DWP spokesperson said. "Where we fall short, we take that seriously and we continue to modernise the service and improve how we work so that cases can be progressed more quickly and effectively. We have no evidence of systemic IT faults which affect calculations. Any parent who disagrees with a decision has the right to challenge it. Safeguarding is something we take very seriously, and our staff are trained to identify mental health risks and take action."