Threshr
Threshr

About Threshr

Threshr is a free UK holiday let calculator that helps property owners and prospective buyers work out whether a short-term rental property is financially viable. Input your region, bedroom count, occupancy, purchase price and mortgage, and the tool models gross income, running costs, income tax, and the letting-day compliance thresholds that determine whether you pay business rates or council tax — all in real time, with no account or email required.

Why it exists

The UK holiday let market has a compliance layer most general property tools ignore. In Wales, letting your property for fewer than 182 days in a year means missing the threshold for business rates — and instead paying council tax at a premium that now reaches 100–150% in many Welsh councils, adding thousands of pounds to annual running costs. England and Scotland have their own 70-day threshold. Missing it quietly is easy; the financial cost is not. Threshr was built to surface this clearly, so owners and buyers can see the full picture before committing.

How figures are sourced and verified

Regulatory data — Land Transaction Tax (LTT) bands, Stamp Duty Land Tax (SDLT) rates, and council tax premium percentages by local authority — is verified against primary government and council sources and dated accordingly. Source references are available via the source references link at the bottom of the calculator page. Figures are reviewed periodically; the current data reflects rates verified in June 2026.

What the calculator covers

  • 40+ regions across Wales, England and Scotland with regional nightly rate benchmarks by bedroom count
  • Wales 182-day and England/Scotland 70-day occupancy threshold tracking, with business rates vs council tax determination and second home premium modelling per local authority
  • Land Transaction Tax (LTT) and Stamp Duty Land Tax (SDLT) estimates at current higher residential rates, updated for the December 2024 LTT changes and October 2024 SDLT surcharge increase
  • Monthly outgoings breakdown covering mortgage, running costs, income tax and council tax or business rates
  • Income tax modelling under current rules — the Furnished Holiday Let (FHL) regime was abolished in April 2025; holiday let income is now taxed as standard rental income, with mortgage interest relief restricted to the 20% basic rate under Section 24

A note on estimates

Threshr provides figures for planning and guidance only. It does not constitute financial, tax, legal or investment advice. Tax calculations are simplified and do not account for your full personal tax position. Regulatory information is verified against primary sources but rules change — always confirm current rates and thresholds with a qualified accountant or solicitor before making property investment decisions.