Accidental Landlord Tax Guide
Moved out and let your home? Income tax like any landlord; CGT time-apportioned with private residence relief; the surcharge if you buy again. Worked example.
The short answer
An accidental landlord is taxed like any other landlord — rent minus expenses at your marginal rate, mortgage interest as a 20% credit — but with three things in your favour: private residence relief shelters most of the capital gain on your former home, the £1,000 allowance covers tiny lets, and you may have a consent-to-let mortgage rather than a buy-to-let one.
You moved for work, inherited a house, could not sell, or moved in with a partner and kept your flat. Nothing in tax law distinguishes you from an investor — but your facts are different, and they matter most on the day you sell.
Income tax: the same rules
- Declare gross rent; deduct allowable expenses; mortgage interest is a 20% credit, not a deduction.
- Register for self assessment by 5 October after the first tax year you receive rent (unless gross rent is under £1,000).
- If gross rent plus any self-employment exceeds £50,000, you are inside Making Tax Digital.
- Council tax and utilities during the gap before the first tenant are allowable; pre-letting repairs within seven years count on day one.
Capital gains: where accidental landlords win
When you sell, the gain is time-apportioned. The years you lived there are exempt under private residence relief, plus the final 9 months of ownership always. Only the let period (less those 9 months) is chargeable — at 18% / 24% after the £3,000 annual exempt amount, reported within 60 days.
| Situation | Result |
|---|---|
| Owned 10 years, lived in for 7, let for 3, £80,000 gain | Exempt: 7 years + final 9 months = 7.75/10. Chargeable: 2.25/10 × £80,000 = £18,000, less £3,000 = £15,000 taxable |
| Higher-rate taxpayer on the above | 24% × £15,000 = £3,600 CGT |
| Same property held by a pure investor for 10 years | Whole £80,000 less £3,000 = £77,000 taxable → £18,480 at 24% |
Lettings relief (up to £40,000) survives only where you shared occupation with the tenant — it no longer applies to a home you moved out of and let whole.
Stamp duty if you buy again
Keeping your old home and buying a new one makes the new one an additional dwelling: the 5% surcharge (8% ADS in Scotland, higher rates in Wales) applies — refundable if you sell the old home within 36 months.
Mortgage and insurance
Tell your lender (consent to let) and switch to landlord insurance — both the consent fee and the premium are allowable. Letting without consent breaches the mortgage terms and can void the insurance.
Selling vs keeping — the tax angle
Each year of letting shifts more of the gain into the chargeable fraction and pushes you further from the 36-month surcharge refund window. Run the CGT calculator with your dates before deciding to hold.
gov.uk private residence relief (HS283) — final 9 months, lettings relief shared-occupancy rule; SDLT higher rates and refund window; MTD threshold; rates from our verified 2026/27 dataset. Checked 31 Aug 2026.
Quick answers
Yes — the same as any landlord. Rent minus allowable expenses is added to your other income and taxed at your marginal rate, with mortgage interest as a 20% credit.
Only on the let fraction of the ownership period, less the final 9 months, less the £3,000 exempt amount. The years you lived there are exempt.
Yes — the new purchase is an additional dwelling. The surcharge is refunded if you sell the old home within 36 months.
Register for self assessment by 5 October after the first tax year with rental income (unless gross rent is £1,000 or less).