The £400,000 round-number anchor: bunching without a stamp duty cliff
HM Land Registry recorded 6,729 residential sales at exactly £400,000 in England and Wales during 2025, against just 1,152 in the £4,999 immediately above it (£400,001-£404,999). That is a 5.8x bunching ratio at a price point that is not an SDLT threshold at all.
The previously published threshold pieces — £125,000, £250,000 and the £500,000 cliff — all sit on real Stamp Duty Land Tax slab boundaries (HMRC). The £400,000 mark does not: it falls roughly in the middle of the 5% slab that runs from £250,001 to £925,000. There is no marginal tax saving from listing at £400,000 instead of £404,999. Yet the bunching here is stronger than at the £250,000 SDLT slab change itself.
Based on 848,775 Land Registry transactions registered for the 2025 calendar year (data fetched 21 May 2026).
The shape of the cliff at £400,000
The histogram around £400,000 in £5,000 buckets across 2025 sales:
| Price bucket | Transactions |
|---|---|
| £380,000-£384,999 | 6,501 |
| £385,000-£389,999 | 6,275 |
| £390,000-£394,999 | 5,855 |
| £395,000 exactly | 3,459 |
| £395,001-£399,999 | 1,727 |
| £400,000 exactly | 6,729 |
| £400,001-£404,999 (deadzone) | 1,152 |
| £405,000 exactly | 2,475 |
| £405,001-£409,999 | 1,470 |
| £410,000-£414,999 | 5,465 |
| £415,000-£419,999 | 5,352 |
Source: HM Land Registry Price Paid Data, 2025 sale dates, England and Wales.
Three features of the pattern matter. First, the £400,000 row contains more sales than any other £5,000 bucket within the £30,000 corridor around it. Second, the £4,999 immediately above the round number contains just 17% of the volume sitting on the round number itself. Third, the secondary round numbers at £395,000 and £405,000 are also visible peaks (3,459 and 2,475 sales), but neither approaches the £400,000 anchor.
The marginal SDLT cost of crossing £400,000
This is the part that distinguishes the £400,000 anchor from the £250,000 and £500,000 cases. Stepping from £400,000 to £405,000 changes the SDLT bill from £10,000 to £10,250 — an extra £250, exactly the standard 5% applied to a £5,000 slice anywhere in the £250,001-£925,000 band. The marginal economics are identical to stepping from £600,000 to £605,000, or from £800,000 to £805,000.
By contrast:
- At £250,000, the buyer steps from a 2% slab to a 5% slab. Pricing at £250,000 instead of £254,999 saves £150 (the 3-percentage-point uplift on the £5,000 slice above the boundary).
- At £500,000, a first-time buyer who paid £499,999 retains FTB relief; one who paid £500,001 loses it entirely. The cliff is worth £5,000 in tax on the worked example in our £500,000 FTB cliff piece.
At £400,000, the equivalent saving from pricing one pound under the round number is zero. Despite that, the bunching ratio is larger than at the £250,000 slab boundary.
Cross-threshold comparison
The pattern across the four threshold pieces, all on 2025 calendar-year data:
| Price point | SDLT effect | At exact | Deadzone | Bunching ratio |
|---|---|---|---|---|
| £125,000 | 0% → 2% slab change | 4,863 | 4,318 | 1.13x |
| £250,000 | 2% → 5% slab change | 10,603 | 3,224 | 3.29x |
| £400,000 | none (inside 5% slab) | 6,729 | 1,152 | 5.84x |
| £500,000 | FTB relief lost | 4,841 | 470 | 10.30x |
The £400,000 ratio sits between the two real SDLT cliffs. Without a tax explanation, the next question is whether the £400,000 anchor is just one example of a wider phenomenon: do non-tax round numbers bunch on their own?
Other round-number anchors with no SDLT trigger
The £50,000-step round numbers above £350,000 are all inside the 5% slab. None of them mark an SDLT threshold for a standard buyer (first-time buyers lose tapered relief above £500,000, which puts £500,000 in a separate category). Bunching at each, again on 2025 sale dates:
| Round number | SDLT trigger? | At exact | Deadzone (next £5k) | Ratio |
|---|---|---|---|---|
| £350,000 | No | 8,229 | 1,842 | 4.47x |
| £400,000 | No | 6,729 | 1,152 | 5.84x |
| £450,000 | No | 6,827 | 843 | 8.10x |
| £500,000 | Yes (FTB) | 4,841 | 470 | 10.30x |
| £550,000 | No | 3,862 | 432 | 8.94x |
| £600,000 | No | 3,132 | 288 | 10.88x |
Across this corridor, the bunching ratio rises monotonically with price. The £600,000 anchor — with no SDLT consequence whatsoever — produces a sharper cliff than the £500,000 FTB threshold. Volume at the round number falls with price (markets thin), but volume immediately above the round number falls faster, which is what drives the ratio higher.
The interpretation favoured by the data: the round number itself is the dominant pricing force above £350,000. SDLT slab boundaries amplify the effect when they coincide with one (£250,000), but they are not a precondition for it.
Year-on-year stability of the £400,000 anchor
The 2025 ratio is not a one-off. Volumes at exactly £400,000 versus the £4,999 deadzone above for each of the last four years:
| Year | At £400,000 | £400,001-£404,999 | Ratio |
|---|---|---|---|
| 2022 | 7,351 | 1,783 | 4.12x |
| 2023 | 6,362 | 1,303 | 4.88x |
| 2024 | 7,026 | 1,381 | 5.09x |
| 2025 | 6,729 | 1,152 | 5.84x |
The pattern is structural across multiple SDLT regimes (the 2022 system, the temporary autumn 2022 thresholds, and the April 2025 reversion). The ratio has drifted slightly higher year on year but the order of magnitude does not move.
Who sells at £400,000
Of the 6,729 transactions at exactly £400,000 in 2025, 3.8% were registered as new-build (257 sales) and 96.2% as existing-stock resale (6,472). In the wider £380,000-£419,999 corridor, new-builds account for 6.8% of sales. New-build supply is therefore under-represented at the £400,000 anchor, consistent with developers pricing at uneven amounts (£399,995 or £402,500) rather than round numbers.
By geography, the £400,000 cluster is dominated by transactions outside the major city cores. Regional breakdown:
| Region (broad postcode classification) | At £400k | Deadzone (next £5k) |
|---|---|---|
| Other England & Wales | 5,872 | 990 |
| London | 652 | 111 |
| Birmingham (B1-B9) | 127 | 27 |
| Manchester (M1-M9) | 78 | 24 |
The £400,000 anchor is mainly a commuter-belt and large-town phenomenon. Top postcode areas at this price point in 2025: Croydon (CR0, 32 sales), Southend / South Essex (SS7, 24), Brighton (BN1, 24), Streatham (SW16, 23) and Bracknell (RG12, 19).
What this means for buyers and sellers
For buyers, an offer at £399,000 against a £400,000 asking price has a £50 SDLT impact (5% on £1,000). The headline saving from undercutting the round number is purely psychological, not fiscal. Pricing pressure at the £400,000 mark is driven by listing conventions and human anchoring, not by HMRC.
For sellers and valuers, the data is consistent with a strong asking-price effect: properties priced for marketing at £400,000 transact at £400,000 in large numbers, while properties priced fractionally above (in the £400,001-£404,999 corridor) are roughly six times rarer. That gap is wider than the comparable gap at the £250,000 SDLT slab boundary, where the actual tax law sits.
A 75% LTV, 5-year fixed mortgage on a £400,000 purchase requires a £300,000 loan. At the Bank of England-quoted average of 4.32% (April 2026 release), a 25-year repayment would carry a monthly payment around £1,635. The Homecost £300,000 mortgage cost guide breaks down the term and rate sensitivities.
Try the postcode tool with a sample £400,000 area: CR0 1AA (Croydon) returns recent transactions, EPC certificates and the local council tax band. For other cost brackets see the £300,000, £400,000 and £500,000 true-cost pillars, or browse the full cost-intelligence category.
This article is general information based on HM Land Registry Price Paid Data and HMRC published rates. It is not legal, tax or financial advice. Speak to a qualified adviser before acting.