Becoming a Landlord for the First Time: A 2026/27 Tax Checklist
A first-time landlord's practical 2026/27 tax checklist — registering for Self Assessment, declaring rental income, allowable expenses, the Section 24 mortgage interest restriction, and what happens when you eventually sell.
Step 1: register for Self Assessment
The moment you have a tenant paying rent, the tax clock starts. If your gross rental income (before any expenses) exceeds £1,000 in a tax year, you need to register for Self Assessment and file a return. Registration should happen by 5 October following the end of the tax year in which letting began — miss this and you risk a "failure to notify" penalty even if you go on to pay the right amount of tax on time.
Below £1,000 gross, the property income allowance can cover you and registration may not be required, but most single-property landlords with a normal rent roll will exceed £1,000 quickly.
Step 2: understand what counts as rental income
You declare gross rental income — the full rent received, before you deduct anything — plus related income like a non-refundable holding deposit or a service charge you collect from the tenant. Expenses are then deducted separately on the return, not netted off before you report the figure.
If you're letting jointly with a spouse or partner, income is normally split according to your beneficial ownership shares — 50/50 by default for married couples and civil partners, unless you've made a formal declaration of a different split with HMRC.
Step 3: know what you can deduct — and what you can't
| Expense type | Deductible against rental income? |
|---|---|
| Letting agent fees | Yes |
| Landlord insurance | Yes |
| Repairs and maintenance (like-for-like) | Yes |
| Ground rent and service charges | Yes |
| Accountancy fees for the letting | Yes |
| Mortgage interest | No — handled via the Section 24 tax credit instead |
| Capital improvements (extension, loft conversion) | No — added to acquisition cost, relevant only for CGT on sale |
Step 4: the Section 24 mortgage interest restriction
This is the single biggest change to catch out landlords who bought before the rules changed, and it still surprises many first-time landlords today: you cannot deduct mortgage interest from rental income before working out your tax. Instead:
- Calculate tax on your full rental profit, as if no mortgage interest had been paid at all.
- Receive a tax credit worth 20% of your mortgage interest for the year, applied after the tax calculation.
For a basic-rate taxpayer, this broadly nets out close to a normal deduction, because the tax saved and the credit given both work out around 20%. For a higher or additional-rate taxpayer, it's a genuine cost — you pay tax at 40% or 45% on the "phantom" profit represented by the mortgage interest, then get only a 20% credit back, meaning the effective tax rate on true rental profit can end up well above the headline income tax band.
Worked example: the Section 24 effect
Consider a higher-rate taxpayer with a rental property generating £14,000 rent a year, £9,000 of annual mortgage interest, and £2,000 of other allowable expenses (agent fees, insurance, minor repairs).
| Item | Amount |
|---|---|
| Rental income | £14,000 |
| Other allowable expenses | £2,000 |
| Taxable rental profit (mortgage interest NOT deducted) | £12,000 |
| Tax at 40% (higher rate) | £4,800 |
| Less: 20% tax credit on £9,000 mortgage interest | £1,800 |
| Net tax due | £3,000 |
The landlord's actual cash profit — rent minus mortgage interest minus other expenses — is only £14,000 − £9,000 − £2,000 = £3,000. Yet the tax bill is also £3,000, meaning effectively all of the real cash profit is absorbed by tax, a direct consequence of paying 40% tax on income that, in cash terms, went straight to the lender as mortgage interest. Model your own figures with
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Open Rental Yield calculatorStep 5: know that CGT is coming eventually
Rental profit tax is an annual, ongoing obligation, but there's a second tax event waiting at the end of ownership: Capital Gains Tax when you sell. Unless the property was your main home for part of your ownership, the whole gain — sale price minus purchase price, minus allowable costs including any capital improvements — is taxable at 18% (basic-rate band) or 24% (above it), after a £3,000 annual exempt amount.
Crucially, this isn't reported on the normal annual Self Assessment timetable — UK residential property gains must be reported and the estimated tax paid within 60 days of completion, using a dedicated CGT UK Property return. First-time landlords who've grown used to the slower rhythm of annual Self Assessment for rental income are often caught out by how fast this deadline arrives.
Choosing between the property income allowance and actual expenses
Alongside the standard "gross income minus actual expenses" approach, first-time landlords with relatively low rental income also have the option of deducting a flat £1,000 property income allowance instead of itemising actual expenses — similar in concept to the trading allowance available to the self-employed. This is worth comparing against your actual costs each year, since it can be simpler and, in a year with unusually low expenses, more generous. However, most landlords with a mortgage, insurance, agent fees and occasional repairs will find their actual allowable expenses comfortably exceed £1,000, making the itemised approach more tax-efficient in practice. You can't combine both — it's actual expenses or the flat allowance, not a mixture of the two, for a given tax year.
Furnished holiday lettings: a different regime entirely
If your first rental property is a genuine holiday let rather than a standard longer-term tenancy, be aware that the furnished holiday lettings (FHL) tax regime — which historically offered more generous treatment, including full mortgage interest deductibility rather than the Section 24 credit restriction — has been phased out for new lettings, with FHL-specific tax advantages abolished from April 2025 onward. First-time landlords letting a holiday cottage or similar short-term let should check the current rules carefully rather than assuming the older, more favourable FHL treatment still applies, since the standard property income rules (including the Section 24 restriction) now apply much more broadly across both long-term and short-term residential lets.
What happens if you inherit or receive a property to let, rather than buying one
Not every first-time landlord starts by purchasing a buy-to-let with a mortgage. If you inherit a property and decide to let it rather than sell it, the same ongoing rental income tax rules described above apply from the point letting begins — you register for Self Assessment, declare gross rental income, and deduct allowable expenses in the normal way. The main difference is on the eventual sale: your acquisition cost for CGT purposes is generally the property's market value at the date you inherited it (or the date of the previous owner's death), not what you originally paid for it, since you didn't buy it in the ordinary sense. This is worth getting a professional valuation for at the time of inheritance, since it becomes the baseline figure for any future capital gain calculation.
Common first-time landlord mistakes
- Netting off the mortgage payment, not just the interest, against rental income — only the interest element of a mortgage payment (converted into the Section 24 tax credit) has any tax relevance; capital repayment is never deductible.
- Forgetting to register for Self Assessment until the tax return deadline is imminent — registration has its own earlier deadline (5 October following the tax year end), separate from the filing deadline.
- Mixing up personal and rental-related bank transactions, making it hard to reconstruct allowable expenses accurately at year end.
- Assuming letting through an agent removes all tax obligations — agents handle the property, not your tax return; the income still needs to be declared by the landlord personally.
- Not budgeting for the CGT bill on eventual sale, treating annual rental profit tax as the only tax cost of being a landlord.
National Insurance and your State Pension record as a landlord
Unlike self-employment, ordinary rental income doesn't attract Class 4 National Insurance and doesn't count toward your State Pension qualifying years in its own right, since letting property isn't generally treated as "running a business" for NI purposes unless it's on a scale and organisation that amounts to a genuine property trading business rather than passive property income. This means a first-time landlord who scales back employed or self-employed work to focus on managing rental properties should check separately whether they're still building sufficient State Pension qualifying years through other means, since rental profit alone typically won't fill that gap. It's a detail that's easy to overlook when the immediate focus is on rental income tax and Section 24, but it matters over the long term.
First-time landlord checklist
- Register for Self Assessment within the deadline if gross rental income will exceed £1,000.
- Set up landlord-specific insurance before the first tenancy starts — standard home insurance won't cover it.
- Keep separate, clearly labelled records for repairs versus capital improvements from day one.
- Get your annual mortgage interest certificate from your lender each year for the Section 24 calculation.
- Budget for tax on rental profit using the post-Section-24 method, not a simple "rent minus mortgage" mental model.
- Plan ahead for the 60-day CGT deadline before you ever agree a sale — don't wait until completion to think about it.
Frequently asked questions
Do I need to register for Self Assessment as soon as I get my first tenant?
You need to register for Self Assessment if your gross rental income (before expenses) exceeds £1,000 in a tax year, or if you have any tax to pay on rental profit even below that. Registration should happen by 5 October following the end of the tax year in which you started letting — for example, if you first received rent in August 2026, you'd normally need to register by 5 October 2027. Don't wait until your first tax return deadline is looming; registering late can trigger penalties even if the tax itself is paid on time.
What rental income do I have to declare?
You declare gross rental income — the full rent received, before deducting any expenses — plus anything else connected to the letting, such as a non-refundable holding deposit, a service charge you collect from the tenant, or income from letting a garage or parking space alongside the property. If you let jointly with a spouse or partner, income is normally split according to your beneficial ownership shares (50/50 by default for married couples unless you've filed a declaration otherwise).
What's the difference between a repair and an improvement, and why does it matter for tax?
A repair restores something to its previous condition — fixing a broken boiler, repainting walls, replacing a worn carpet like-for-like — and is deductible against your rental income in the year it's incurred. An improvement adds something new or enhances the property beyond its original state — an extension, a loft conversion, upgrading a bathroom to a noticeably higher standard — and isn't deductible against rental income at all; instead it's added to your acquisition cost and only reduces tax when you eventually sell and calculate Capital Gains Tax. Misclassifying a big improvement as a 'repair' is one of the most common first-time landlord mistakes on a tax return.
What expenses can I actually deduct against rental income?
Typical allowable expenses include letting agent fees, landlord insurance, repairs and maintenance (not improvements), ground rent and service charges, accountancy fees for managing the letting, utility bills you pay on the tenant's behalf, and a proportion of costs like phone calls or travel directly related to managing the property. Mortgage interest is treated separately under Section 24 rather than as a straightforward deductible expense — see below.
How does the Section 24 mortgage interest restriction work?
Since the restriction was fully phased in, landlords can no longer deduct mortgage interest from rental income before calculating tax. Instead, you calculate tax on the full rental profit as if no mortgage interest had been paid, then receive a tax credit worth 20% of your mortgage interest, applied after the tax calculation. For a basic-rate taxpayer this broadly nets out the same as a straightforward deduction, but for higher and additional-rate taxpayers it means paying tax at 40% or 45% on the 'phantom' profit represented by the interest, before getting only 20% of it back as a credit — which can push some landlords into a higher marginal tax rate on their rental profit than the headline income tax rate suggests.
Should I hold my rental property personally or through a limited company?
It depends on your income tax band, your mortgage arrangements, and your long-term plans. Personal ownership is simpler and avoids company administration, but exposes higher-rate taxpayers to the full Section 24 restriction. A limited company structure isn't subject to Section 24 in the same way (companies deduct mortgage interest normally against Corporation Tax) but comes with company running costs, potentially higher mortgage rates for company buy-to-let borrowing, and different rules for extracting profit as a director. First-time landlords with one property and a standard income are often better off starting personally and reviewing the structure only if they plan to scale up.
Will I owe Capital Gains Tax if I sell the property later?
Almost certainly, if the property has risen in value and was never your main home. You'll owe CGT on the gain (sale price minus purchase price and allowable costs), taxed at 18% within your remaining basic-rate band and 24% above it, after deducting the £3,000 annual exempt amount. Crucially, any gain on a rental property sale must be reported and paid within 60 days of completion using a separate CGT UK Property return — this catches many first-time landlords out because it's a much faster deadline than the annual Self Assessment timetable they're used to for rental income.
Do I need landlord-specific insurance, and is it tax deductible?
Yes to both. Standard home insurance typically doesn't cover a let property, so you need specific landlord insurance covering buildings, and often contents if you're letting furnished, plus optional cover like loss of rent or legal expenses. The premiums are a fully allowable expense against your rental income, deducted in the year you pay them.
What records should I keep from day one?
Keep every invoice and receipt for expenses (repairs, agent fees, insurance, ground rent), a record of all rent received with dates, your mortgage interest certificate from the lender each year (needed for the Section 24 calculation), and separately, receipts for any capital improvements, since those only become relevant later for CGT rather than annual rental profit. HMRC can ask to see records going back several years, and reconstructing them retrospectively is far harder than keeping a simple running spreadsheet or using landlord accounting software from the start.
Does letting a room in my own home follow the same rules?
No — letting a room in your own home, where you continue to live there, falls under the separate Rent a Room Scheme, which allows up to £7,500 a year of gross rental income tax-free with no expenses deducted, rather than the ordinary property income rules covered in this guide, which apply to letting a whole separate property you don't live in.
What if my rental property makes a loss in the early years?
Rental losses (where allowable expenses exceed rental income, calculated before the Section 24 mortgage interest credit) can be carried forward and offset against future rental profits from the same UK property business, though they can't generally be offset against other income like salary. It's still worth declaring a loss year accurately on your return, since the carried-forward loss can meaningfully reduce tax in a later, more profitable year.
Related reading
Limited Company vs Personal Buy-to-Let in 2026: Which Wins?
Personal landlords pay up to 40% or 45% income tax with mortgage interest only a 20% credit, while a company pays 19% Corporation Tax to GBP 50,000. Here is how the two structures compare on a worked GBP 12,000 rental profit.
Section 24 Mortgage Interest Relief: Still a Problem for Landlords in 2026?
Section 24 replaced mortgage interest deduction with a 20% tax credit in 2020. In 2026 it still hits higher-rate landlords hard — here's exactly how much extra tax you're paying and what to do about it.
Selling a Buy-to-Let Property: Working Out Your CGT Bill (2026/27)
A step-by-step walkthrough of calculating Capital Gains Tax when you sell a buy-to-let property in 2026/27 — allowable costs, the 18%/24% rates, the 60-day reporting deadline, and a full worked example.