beta This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Stamp Taxes on Shares Manual

Compliance: Stamp Duty interest: Calculation of interest

The rate of interest applying to late payment of stamp duty is the rate applicable under FA89/S178 and is set by the Treasury.

No interest is payable if the interest totals less than £25. Calculations of interest are rounded down to the nearest multiple of £5.