Overview
- Freedom of Information data show HMRC sent more than 1.32 million simple assessment letters in 2023/24, up from 675,000 in 2021/22.
- The average underpayment identified via simple assessments has risen from about £600 in 2019/20 to roughly £920 in 2023/24.
- Separately, HMRC is writing to nearly 900,000 people with more than £3,500 in savings to verify reported interest, with letters framed as requests for clarification rather than penalties.
- Experts link the rise in demands to fiscal drag from the frozen £12,570 personal allowance and higher state pension and savings interest, with thresholds currently set to remain frozen until 2031.
- HMRC advises recipients to check the figures, contact the department by phone or post if unsure, and seek instalment plans if they cannot pay, while a 2027 exemption is planned for those whose only income is the state pension.