HMRC interest rates are set, by law, to rise and fall with the Bank of England base rates.
Late payment interest is set at base rate plus 2.5%. As the base rate has risen to 3%, this rate increases to 5.50% from 22 November 2022.
Repayment interest is set at base rate minus 1% but with a “minimum floor” of 0.5%. The repayment interest rate increases to 2.00% from the same date.
These rates apply to most taxes, including income tax, NIC contributions, CGT, SDLT, IHT and corporation tax (CT). However, slightly different rates apply for CT quarterly and non-quarterly instalment payments.
The Welsh Revenue Authority rates for land transaction tax and landfill disposals tax are also being increased.
https://www.gov.uk/government/news/hmrc-late-payment-interest-rates-to-be-revised-after-bank-of-england-increases-base-rate–8 (CT instalment payments)
https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments/rates-and-allowances-hmrc-interest-rates (taxes generally)
https://gov.wales/pay-land-transaction-tax and https://gov.wales/pay-landfill-disposals-tax (Welsh taxes)