Real cases from Stamp's files, with names, firms, addresses and dates removed. In each one, a single answer moved the stamp duty by tens of thousands of pounds, and a single-figure calculator would have shown one end of the range with nothing to say the other existed.
of purchases checked in 2026 were non-standard, so nearly half needed a closer look*
median gap between the best and worst case on a non-standard purchase*
non-standard cases could owe nothing in the best case, if the right relief applies*
*Stamp.Expert data for checks completed in 2026, up to November 2026. Non-standard means something in the client's answers makes the stamp duty uncertain. Best and worst cases are the two ends of the range shown to the client; the amount actually due depends on the facts and, for non-standard purchases, on advice from a tax adviser. Stamp.Expert does not give tax advice.
Every range bar is drawn on the same scale, from £0 to £178,500.
A warning, not a final figure.
Each range is what Stamp showed the client when they finished their answers: the lowest and highest stamp duty the purchase could carry, on the rates in force at the time. The right figure sits somewhere in the range and needs a tax adviser to confirm it.
Timestamped, not a fee-earner's note of a phone call.
In plain English.
An independent adviser, their own adviser, or advice declined with the risk warning accepted.
A short call: the client journey, a standard and a non-standard result, and the record your file receives.
