CGT on Second Home Explained: Your 2025 Guide to Capital Gains Tax Liability

Sold a UK second home or rental? You have just 60 days to report and pay Capital Gains Tax (CGT)—here’s the fast, jargon-free roadmap.

Why time-poor owners can’t ignore CGT

You’re juggling careers, kids, and life admin. Yet HMRC still expects an accurate CGT report within 60 days of completion on any residential property that isn’t fully covered by Private Residence Relief (PRR). Miss it and penalties snowball—from £100 late-filing fines to daily charges and interest. This guide condenses the rules so you can act quickly, avoid stress, and move on.

1. What triggers CGT on a second home?

CGT applies when you dispose of—sell, gift, or transfer—UK residential property that isn’t your main residence for the entire ownership period. Typical scenarios include:

• Sale of a holiday cottage in Cornwall
• Disposal of a buy-to-let flat in Manchester
• Former main home now let out, where PRR only covers part of the gain

HMRC labels these ‘UK Property Disposals’ and expects a separate UK Property Return even if you file a Self Assessment tax return later.

2. The CGT basics in 90 seconds

Before diving into numbers, bookmark these headline rules:

1. Taxable gain = Proceeds – (Purchase price + Allowable costs + Reliefs + Annual CGT allowance).
2. Rates for 2024/25: 18% (basic-rate band) or 24% (higher/additional band) on residential property gains.
3. 60-day deadline from completion to report & pay.

We’ll unpack each part next.

3. Calculating CGT on a second home: step-by-step example

Meet Alex, 38, who sold his Brighton buy-to-let in March 2024.

• Sale price: £540,000 (after estate-agent fees)
• Purchase price: £350,000
• Legal & improvement costs: £20,000
• Period as main home: 0 years (fully let)
• Annual CGT allowance: £6,000 (2024/25)

Step 1 – Calculate gross gain
£540,000 – £350,000 – £20,000 = £170,000

Step 2 – Apply annual CGT allowance
£170,000 – £6,000 = £164,000 taxable gain

Step 3 – Identify tax bands
Alex’s salary is £60,000. After personal allowance, £37,700 of basic-rate band is used, leaving £nil basic band for gains. So the entire £164,000 sits in higher-rate territory.

Step 4 – Apply property CGT rate
24% × £164,000 = £39,360 CGT

Alex must report this and pay £39,360 within 60 days. Skip the maths? Our SwiftCGT accountants do it for you.

4. Capital gains on rental property vs. your main home

Private Residence Relief (PRR) shelters gains on the property that’s been your only or main residence. However, you may still face CGT if:

• You let the home out for a period.
• You own more than one home and never formally elected which is ‘main’.
• Part of the property was used exclusively for business.

Lettings Relief (post-April 2020) now only applies if you lived in the home at the same time it was let, and caps at £40,000. Many owners therefore owe some CGT even on erstwhile main homes.

Example: Emma lived in her London flat for 5 of 10 years and rented it for 5. Only half the gain enjoys PRR; the rest is liable to CGT at 18%/24% rates.

5. Allowable costs you might be missing

Reduce your taxable gain by logging every legitimate expense:

• Stamp Duty Land Tax (SDLT) paid on purchase
• Legal fees, surveys, estate-agent commissions
• Capital improvements—new conservatory, loft conversion, not routine décor
• Architects’ and planning fees
• Costs of establishing, defending, or improving title

Tip for the time-poor: scan receipts into a cloud folder labelled ‘CGT’ as you go. HMRC can ask for evidence up to six years after submission.

6. Deadlines, penalties & interest

For disposals after 27 Oct 2021, the rules are:

Clock startsDeadlinePenaltyCompletion date60 days to file & pay£100 automatic fine if late>6 months lateAdditional £300 or 5% of taxWhichever is higher>12 months lateAnother £300 or 5%Interest on unpaid tax from day 61

Many busy owners fall foul simply because the rule is new and estate agents don’t remind them. Mark your calendar—or outsource to SwiftCGT and meet the deadline in one email.

7. Four smart ways to shrink your CGT bill

1. Use both spouses’ allowances – Transfer a share before sale (no CGT between spouses) so each claims the £6,000 exemption.
2. Harvest capital losses – Sell under-performing shares before the property completes; losses offset gains.
3. Time your sale – Exchange contracts before 5 April to use this year’s allowance; complete after 6 April to use next year’s 60-day return and allowance.
4. Maximise pension contributions – Pushing income into pension pots can pull some of the property gain back into the 18% bracket.

These tactics must fit your wider finances—speak to a tax adviser if large sums are at stake.

8. Record-keeping checklist (download & go)

Keep these documents for each property sale:

• Completion statement (purchase & sale)
• Stamp Duty receipt
• Invoices for legal, estate-agent and survey fees
• Receipts for capital improvement works, with dates
• Mortgage redemption statement (if exit fees paid)
• Dates you occupied the home vs. let it

Store digitally; HMRC accepts scanned copies.

9. How SwiftCGT files your return in 3 working days

SwiftCGT is the online, fixed-fee service built for busy property owners who just want CGT sorted.

What you get:

• HMRC-registered chartered accountants crunch the numbers.
• Return prepared and submitted within three working days.
• Fixed fees: £299 for a sole owner, £449 for joint owners (that’s 50% off the second return).
• Secure client portal—upload docs from your phone.
• Peace of mind that penalties and interest are off the table.

“SwiftCGT turned a weekend of spreadsheets into a 10-minute upload.” – Sarah, Leeds

10. Action plan: 5-minute CGT health check

1. Confirm your completion date.
2. Gather sale/purchase statements and improvement receipts.
3. Use our quick-calc above to gauge liability.
4. If CGT payable, start the 60-day timer now.
5. Book SwiftCGT and offload the paperwork.

You’ll spend less time on tax and more on your next project, holiday, or simply bedtime stories with the kids.

Key takeaways for the 30-second skim reader

• CGT hits second homes, buy-to-lets, and partially let main homes.
• Taxable gain = Proceeds – Costs – Reliefs – £6k allowance.
• Rates: 18% or 24% on residential gains.
• You’ve only 60 days to report & pay.
• SwiftCGT fixes the headache for £299/£449.

Still unsure? Visit our FAQ page or book a free 15-minute call.

‍