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?

Permanent increase to penalty interest rates

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%.

Muir & Addy is a partnership registered to carry out audit work by the Institute of Chartered Accountants in Ireland (ICAI). Chartered Accountants Ireland is the operating name of ICAI.

Details of our audit registration can be viewed at www.auditregister.org.uk, under reference number 223287.

Chartered Accountants in Ireland (ICAI)