Stamp duty must be paid within 14 days of buying a property or piece of land. Typically, if using a solicitor or conveyancer, they will handle the payment for you. Failure to pay within this timeframe can lead to penalties and interest charges. This rule applies to Stamp Duty Land Tax (SDLT) in England and Northern Ireland; Scotland and Wales have their own versions of this tax with similar timing requirements. The payment is due usually on the completion date of the transaction or an 'effective' transaction date such as possession or first rent payment due date. In summary: Stamp duty is paid within 14 days after the property purchase is completed, often handled by the solicitor, and late payment can incur penalties.