STSM151020 - Compliance: introduction: stamp duty - background
An instrument is not ‘duly stamped’ in accordance with section 14(4) Stamp Act 1891 unless it has been stamped with the Stamp Duty payable, together with any penalty and interest due (see STSM141030). The instrument cannot be stamped until the Stamp Duty, penalty and interest are paid in full (see STSM141020).
If an instrument is presented for stamping within 30 days of the date of execution, no penalty is due. If the Stamp Duty is paid in full within 30 days of the date of execution, no interest is payable. See STSM152020 for treatment of part payments.
The current interest and penalty regime was introduced by Finance Act 1999 and only applies to instruments executed on or after 1 October 1999.