CGT planning in Stanmore: the portfolio landlord's single-disposal decision, and why most HA7 sales overpay by £15,000+

Stanmore CGT is not a downsizer problem. Unlike Harrow on the Hill, where the dominant scenario is a long-hold owner-occupier disposing of a family home, HA7's CGT events are driven by portfolio rebalancing: landlords selling one BTL to redeploy the equity into a better asset, a different area, or a refinanced SPV structure. The arithmetic is severe. Stanmore BTLs acquired in 2005–2012 for £280,000–£420,000 now typically sit at £680,000–£900,000. Gross gains on disposal run £350,000–£550,000 per property. At the higher-rate residential CGT rate of 24%, the bill on a single HA7 disposal is routinely £75,000–£120,000 — before any reliefs or planning. This is not a tax burden to absorb passively; it is the largest single tax event most Stanmore landlords experience, and it happens repeatedly across a portfolio's life.

Three specific actions, taken before exchange rather than after, consistently move the tax figure by five-figure amounts. The first is spousal rebalancing. Where a Stanmore BTL is held in a higher-rate taxpayer's sole name, transferring a share (or the whole beneficial interest) to a basic-rate or non-earning spouse before exchange uses a second £3,000 annual exempt amount and moves part of the gain from 24% to 18%. On a £450,000 gain split 50/50 between a higher-rate and basic-rate spouse, the tax figure drops from approximately £107,280 to approximately £94,440 — a £12,840 saving from a structural move with no transaction cost (inter-spouse transfers are no-gain/no-loss under TCGA 1992 s58, and no SDLT applies). The move must be made before exchange, not after; HMRC's position is that backdating beneficial interest for CGT purposes does not work.

The second is improvement base cost reconstruction. Stanmore BTLs that have been held 15-plus years have almost always had capital improvement work — loft conversions, extensions, rewiring, kitchen upgrades beyond cosmetic replacement. Much of this was carried out without the owner realising it would one day be CGT-relevant, which means invoices and Building Control records are often scattered or missing. Harrow Council's planning and Building Control records are searchable online back to around 1998, and physical records can be retrieved earlier via freedom of information request. A specialist systematically pulls these records, identifies qualifying capital expenditure (not ongoing maintenance), and reduces the CGT base gain in proportion. Typical recovery on a 15-year-held HA7 BTL is £30,000–£75,000 of documented improvement — which at 24% is £7,200–£18,000 of tax saved.

The third is timing against the annual exempt amount and across tax years. A Stanmore landlord selling two BTLs in close succession often schedules both completions in the same tax year purely because that is when the buyer contracts were signed. Splitting completions across two tax years (one before 5 April, one after) doubles the available annual exempt amount and can also give a basic-rate-spouse's unused basic-rate band a second year of use. On two HA7 disposals totalling £800,000 of gain, the timing-only saving is typically £2,500–£4,500 of additional AEA plus potentially £5,000–£15,000 of band-use saving depending on income patterns. None of this requires restructuring the disposal itself — just coordinating the exchange and completion dates with the tax calendar.