The Ministry of Defence has flagged and rejected more than £211 billion in suspicious invoices over the past three years, as it ramps up efforts to combat financial fraud within one of the government’s most complex and high-value departments.
According to official figures obtained via a Freedom of Information (FOI) request and analysed by the Parliament Street think tank, the MoD rejected a total of 8,918 invoices, citing concerns over invalid pricing, tax anomalies, missing supplier data, duplicate entries, and inactive purchase orders. The total value of the rejected invoices reached £211,649,900,000.
While 5,063 of the flagged invoices were later corrected and resubmitted, 3,855 were permanently rejected, highlighting the scale of attempted or accidental misbilling within the ministry’s procurement system.
The revelations follow a string of high-profile fraud cases that have rocked the MoD’s internal accounting and financial oversight systems.
In April, former corporal Aaron Stelmach-Purdie was sentenced to prison for orchestrating a £911,677 fraud by exploiting the MoD’s staff expenses platform. The court heard that he manipulated allowance claims, pocketing over £550,000 for himself.
Just two months later, army soldier Andrew Oakes was convicted of stealing more than £300,000, using his position as a financial administrator to forge cheque stubs and redirect funds to personal accounts. The stolen money was used to purchase multiple high-end vehicles, including three Teslas, a Mini Cooper, and a Nissan Qashqai.
These cases have prompted calls for tighter financial controls and modernisation of verification systems, with growing consensus around the role of AI and machine learning in fraud prevention.
Jason Kurtz, CEO of e-invoicing platform Basware, said the scale of rejected invoices highlights the vulnerability of public sector finance systems.
“When fraud is suspected, we often see large fluctuations in billing as criminals exploit stolen or cloned credentials,” Kurtz explained. “Blocking payments is only half the battle — the resource burden of investigating fake or incomplete invoices is enormous.”
He called for greater deployment of AI-powered verification tools that can vet invoices before they enter the payment system, reducing the burden on overstretched finance teams.
Dr Janet Bastiman, chief data scientist at Napier AI, added that invoice fraud is a common tactic used by organised crime to siphon funds from high-volume government departments.
“Malicious actors frequently use fake paperwork and rogue bank accounts to fuel money laundering and illicit operations,” Bastiman said. “Government departments managing thousands of supplier payments a day are obvious targets. AI-powered anomaly detection offers a proactive way to catch suspicious transactions before the damage is done.”
With the MoD facing increasing scrutiny over its financial management, defence officials are under pressure to strengthen invoice auditing systems and modernise their approach to procurement oversight.
The sheer volume and value of flagged invoices suggest that existing safeguards — while catching many of the most egregious examples — are not fully equipped to prevent fraud at scale.
The findings come at a time when public trust in defence spending remains fragile, and fiscal discipline is under intense political focus. As the MoD contends with rising operational costs and evolving global threats, its financial resilience may increasingly depend on its digital defences as much as its physical ones.
