Private Residence Relief & Lettings Relief Calculator: CGT When You Let a Former Home

If you lived in the property before letting it, part of the gain is usually tax-free. Private residence relief (PRR) exempts the share of the gain that matches the time the house was your only or main home, and HMRC’s helpsheet HS283 adds a rule that catches many former owner-occupiers by surprise: “The final 9 months of your period of ownership always qualify for relief, regardless of how you use the property in that time, as long as the dwelling house has been your only or main residence at some point.”

How the calculation works

• Exempt months = months lived in as your main home + the final 9 months (capped at the total ownership). The exempt share of the gain is that fraction of the whole gain.
• Lettings relief only applies where “part of the dwelling house has at some time in your period of ownership been let as residential accommodation at the same time that another part of the dwelling house was your only or main residence” — HS283 is explicit that “Letting relief does not apply where the whole of the dwelling house was let for a time.” Where it does apply it is the lowest of the PRR already given, £40,000, and the gain attributable to the letting.
• Chargeable gain = gain minus both reliefs; the £3,000 annual exempt amount comes off before the 18% or 24% residential rates.

Why “lettings relief abolished” is half right

Before April 2020 lettings relief was available to landlords who had moved out and let the whole house. Since then it is limited to shared occupation, which is why most accidental landlords now get PRR for the years they lived there, the final nine months, and nothing more. The calculator applies the current rule; if the whole property was let after you moved out, leave the shared-occupation switch on “No”.

Before you sell

The full disposal calculation — costs, improvements, both owners’ allowances — is on the capital gains tax calculator, and the 60-day reporting clock on the 60-day deadline calculator. If you are thinking of gifting rather than selling, the gifting guide explains why the same gain still arises.

Rules and quotes from HMRC helpsheet HS283 (2026) and gov.uk CGT rates, from the same data file as our other calculators (checked 2026-08-29). Months are used as the unit throughout; HMRC works in days, so treat the result as an estimate. General information, not advice.