The government has released statistics around overpayments.
‘Fraud and error in the beneft system, Financial Year Ending (FYE) 2025’
The total rate of benefit expenditure overpaid in FYE 2025 was 3.3% (£9.5bn), compared with 3.6% (£9.7bn) in FYE 2024. The total rate of benefit expenditure underpaid remained at 0.4% in FYE 2025 (£1.2bn), the same as in FYE 2024 (£1.1bn). Overpayments can be Fraud, Claimant Error(CE) or Official Error(OE).
Overpayments due to Fraud were 2.2% (£6.5bn) in FYE 2025, compared with 2.7% (£7.3bn) in FYE 2024.
Overpayments due to Claimant Error were 0.7% (£1.9bn) in FYE 2025, compared with 0.6% (£1.6bn) in FYE 2024.
Overpayments due to Official Error were 0.4% (£1.0bn) in FYE 2025, compared with 0.3% (£0.8bn) in FYE 2024. The two largest areas of overpayments
Universal Credit overpayments- 9.7% (£6.35 billion)

Housing Beneft overpayments- 7.2% (£1.1 billion)

Remember around £13 billion goes unclaimed claimed by claimants each year in means tested benefits alone.