Permanent increase to penalty interest rates
The new tax year saw a change to the way interest on late paid taxes is calculated. What’s changed and what are the new charges?

Prior to 2025/26, interest was charged at the Bank of England base rate plus 2.5% on most underpaid taxes. In a push for unpaid tax bills to be settled, it was announced at the 2024 Autumn Budget that this would change to the base rate plus 4% from 6 April 2025. The government says the rate of late payment interest encourages prompt payment and ensures fairness for those who pay their tax on time.
From 6 April 2025 the following rates apply:
- Late corporation tax paid quarterly - 7%
- Late payment interest on other taxes - 8.5%
There is no corresponding change to the way repayment interest rates are calculated, i.e. the base rate minus 1%, with a lower limit of 0.5%.
Related Topics
-
Multiple agents for MTD ITSA will be permitted
-
One-person companies and the employment allowance
The NI employment allowance has increased from £5,000 to £10,500. The bad news is that companies with only one person who’s also a director on their payroll aren’t entitled to it. How can they qualify with just one simple low-cost step?
-
HMRC pauses some refund claims for agents
Due to security concerns, HMRC has warned that it will not process refund claims made by authorised agents. What’s going on and what alternatives are available?