An estimated 887,000 individuals in the UK are being contacted by HM Revenue and Customs (HMRC) concerning tax owed on savings interest. These letters are being issued to savers whose accumulated interest has surpassed their Personal Savings Allowance (PSA). The precise amount of tax due is contingent upon individual earnings, the total interest generated, and the timing of its distribution.
Understanding the Tax Notices
HMRC is leveraging its automated systems to identify individuals whose savings interest exceeds the established tax-free thresholds. The communication from HMRC takes the form of demand letters, prompting recipients to address potential underpayments of tax. The tax authority is systematically reviewing financial situations to determine liabilities.

Threshold for Contact: Letters are reportedly being sent to individuals with £3,500 or more in savings accounts, though the trigger is the interest earned exceeding the PSA, not the balance itself.
Factors Influencing Tax Due:
Personal income level
Total interest earned from savings
When interest was paid out (e.g., lump sum vs. annual payments)
Scope of HMRC's Reach: HMRC has the capacity to pursue tax owed from previous tax years if underpayments are discovered.
Types of Accounts Affected
The tax liability extends across a variety of savings and investment vehicles. HMRC has identified the following as potentially contributing to interest that could exceed the PSA:
Bank and building society accounts
Savings and credit union accounts
Unit trusts, investment trusts, and open-ended investment companies
Peer-to-peer lending
Payment protection insurance (PPI)
Government or company bonds
Life annuity payments
Certain life insurance contracts
The Personal Savings Allowance (PSA)
The PSA allows individuals to earn a certain amount of savings interest tax-free each year.

Basic-rate taxpayers: Can earn up to £1,000 in interest annually without tax.
Higher-rate taxpayers: Have an allowance of £500 per year.
Additional-rate taxpayers: Receive no PSA and are taxed on all savings interest earned outside of tax-free accounts.
The PSA thresholds have remained unchanged for over eight years, while interest rates have risen, leading to more savers exceeding their allowances.
Fixed vs. Accessible Accounts
The structure of savings accounts can significantly impact how interest is treated for tax purposes.

Fixed-term accounts: Interest may be paid out in a lump sum upon maturity. If a fixed account spans multiple tax years, the entire interest payment can be attributed to a single tax year, potentially pushing it above the PSA for that year.
Easy-access accounts: While interest is typically paid out more frequently, it is still possible for individuals to exceed their PSA even with these types of accounts, especially with rising interest rates.
HMRC's Detection Mechanism
HMRC possesses the capability to automatically detect interest accrued on savings. This allows them to identify accounts where interest earnings may have surpassed the PSA.
"HMRC has the ability to automatically detect interest on savings accrued in your bank account, and if you exceed a certain threshold, you will automatically be issued a notice for an additional tax bill."
Expert Commentary and Implications
The increased issuance of these letters is attributed to a combination of rising interest rates and stagnant PSA thresholds. This confluence of factors means that even modest savings balances can now generate interest liable for taxation.

"Rising interest rates combined with frozen allowances mean that even moderate savings balances, particularly in fixed-term accounts, can now trigger a tax charge."
For those employed or receiving a pension, HMRC may adjust their tax code to automatically collect any owed tax.
Conclusion
HMRC's outreach signifies a concerted effort to ensure tax compliance on savings interest. The letters serve as a notification for individuals whose savings interest has, due to rising rates and unchanged allowances, potentially incurred a tax liability. Recipients are advised to review their savings interest and tax codes to understand their specific situation and address any discrepancies.
Key takeaway: The tax is on the interest earned, not the savings balance.
Actionable insight: Individuals should be aware of their PSA and how different account types affect interest calculation for tax purposes.
Sources Used
Express.co.uk: Published November 8, 2025. https://www.express.co.uk/finance/personalfinance/2131472/hmrc-warning-people-with-3500-savings
ChronicleLive (1): Published October 6, 2025. https://www.chroniclelive.co.uk/news/cost-of-living/hmrc-issuing-demand-letters-savers-32621174
ChronicleLive (2): Published July 7, 2025. https://www.chroniclelive.co.uk/news/cost-of-living/hmrc-demand-letters-being-sent-32008496
ChronicleLive (3): Published January 5, 2026. https://www.chroniclelive.co.uk/news/cost-of-living/hmrc-demand-letter-sent-savers-33165981
RAMSAFE: Published January 8, 2026. https://ramsafe.co.uk/hmrc-demand-letters-savers-3500/
Express.co.uk: Published April 11, 2025. https://www.express.co.uk/finance/personalfinance/2040266/hmrc-savings-interest-tax-letters
NottinghamPost: Published November 9, 2025. https://www.nottinghampost.com/news/uk-world-news/warning-people-over-3500-bank-10631552
Mirror.co.uk: Published April 7, 2025. https://www.mirror.co.uk/money/hmrc-tax-bill-letters-could-35012011
DailyStar.co.uk: Published April 8, 2025. https://www.dailystar.co.uk/news/uk-news/hmrc-sends-demand-letters-people-35017411
GazetteLive: Published May 6, 2025. https://www.gazettelive.co.uk/news/uk-world-news/hmrc-warning-anyone-3500-more-31579926
Brave (pie.tax): Seen on Brave. https://www.pie.tax/tax-pible/hmrc-tax-letters-for-savings-interest
LeedsLive: Published June 8, 2025. https://www.leeds-live.co.uk/news/cost-of-living/hmrc-issues-tax-demand-letters-31811733
BirminghamMail: Published May 18, 2025. https://www.birminghammail.co.uk/news/cost-of-living/hmrc-sending-letters-people-3500-31667351