You normally pay stamp duty shortly after you complete the purchase of a property, and there is a strict legal deadline.

Quick Scoop: When do you pay stamp duty?

In the UK (Stamp Duty Land Tax on property in England and Northern Ireland):

  • You (or your solicitor) must file a stamp duty return and pay any tax within 14 days of the “effective date” of the transaction.
  • The “effective date” is usually the completion date (when you get the keys and the property legally changes hands), though in some cases it can be earlier, for example:
    • When you’re entitled to take possession.
    • When the first rent payment is due on certain leases.
    • When the purchase is “substantially completed” (90% or more of the price paid).
  • If the 14‑day deadline falls on a weekend or bank holiday, the payment must reach HMRC by the previous working day.

Most buyers never handle the payment directly:

  • Your solicitor or conveyancer usually collects the money from you before completion , then submits the return and pays HMRC on completion day or very soon after.
  • You still remain legally responsible if something goes wrong or is late.

If you miss the deadline:

  • HMRC can charge penalties and interest :
    • An initial fixed penalty once you’re late.
    • Further penalties (for example, 5% of the unpaid tax after several months of delay, and again after a year), plus daily interest until it’s fully paid.

So in everyday terms: you budget to have the stamp duty money ready by completion , your solicitor usually pays it for you on or right after that day, and the law requires that HMRC receives the return and payment no later than 14 days from completion/effective date.

Bottom line: you don’t pay stamp duty at offer or exchange; you pay it at, or just after, completion — but always within that 14‑day legal window.