New Landlord Tax Guide: Everything You Need to Know in Your First Year

A new landlord must register rental income with HMRC, declare it through Self Assessment by 31 January after the tax year it arises, and pay income tax on the profit at their marginal rate after deducting allowable expenses. Letting a property for the first time turns you into a taxpayer with new reporting duties, and getting the basics right in year one prevents penalties, missed deductions, and stressful corrections later. This new landlord tax guide, written by Blue Tick Accountants, a Guildford-based UK tax advisory and accountancy practice, explains how to register with HMRC, what counts as taxable rental profit, which expenses you can claim, how the Section 24 mortgage interest rules work, and what Making Tax Digital means for first-time landlords from 6 April 2026. By the end you will know exactly what HMRC expects in your first year of letting.

Key Takeaways

• A new landlord must notify HMRC of rental income by 5 October following the end of the tax year in which letting began, and file the first Self Assessment return by 31 January.
• Rental profit is taxed at your marginal income tax rate of 20%, 40%, or 45% in 2026/27, after deducting allowable expenses.
• The £1,000 property allowance means rental income up to £1,000 a year does not need to be declared at all.
• Mortgage interest is no longer a deductible expense; instead landlords receive a 20% tax credit on finance costs under the Section 24 rules.
• From 6 April 2026, landlords with qualifying property income above £50,000 must keep digital records and submit quarterly updates under Making Tax Digital for Income Tax.
• In the worked example, a higher-rate landlord with £14,400 rent and £6,000 of mortgage interest pays £3,600 income tax after the finance cost credit.

How Do You Register as a New Landlord with HMRC?

A new landlord registers for Self Assessment by notifying HMRC no later than 5 October following the end of the tax year in which rental income first arose. Registration is the legal trigger for everything that follows, so it should be your first administrative task once a tenant moves in.

If you let a property between 6 April 2026 and 5 April 2027, you must tell HMRC by 5 October 2027 and file your first Self Assessment tax return by 31 January 2028. Registration is done online through the government gateway, after which HMRC issues a Unique Taxpayer Reference (UTR) that identifies you on every future return. Missing the notification deadline can trigger a "failure to notify" penalty based on the tax due, so it pays to register promptly rather than waiting until the return itself is due.

You do not need to register if your total rental income for the year is £1,000 or less, because the property allowance covers it automatically. Above that level, registration is mandatory even if your property makes a loss, because HMRC needs the return to record the loss and carry it forward against future rental profits.

What Counts as Taxable Rental Income and Profit?

Taxable rental profit is your total rental income for the tax year minus your allowable expenses, and it is added to your other income and taxed at your marginal rate of 20%, 40%, or 45% in 2026/27. Understanding the difference between income and profit is the foundation of getting your first return right.

Rental income includes the rent itself plus any associated payments such as charges for services, use of furniture, or contributions towards bills. Income is taxed on an "arising" basis, meaning rent counts for the tax year in which it falls due, not necessarily when it lands in your account. A first-time landlord starting buy-to-let part way through a year only declares the rent relating to the period they actually let the property.

The property allowance gives every individual £1,000 of tax-free property income a year. If your gross rents are between £1,000 and the point where claiming actual expenses produces a lower figure, you can elect to deduct the £1,000 allowance instead of itemising costs. For most landlords with a mortgage and running costs, claiming actual expenses produces a far better result, but the allowance is valuable for those letting a single room or a low-rent property with minimal outgoings.

Which Expenses Can a New Landlord Claim?

A new landlord can deduct any expense incurred wholly and exclusively for the rental business, including letting agent fees, repairs and maintenance, landlord insurance, ground rent, service charges, and accountancy fees. Claiming every allowable cost is the simplest legitimate way to reduce your tax bill in year one.

Allowable revenue expenses commonly include letting and management agent fees, property repairs and maintenance (but not improvements), buildings and contents insurance, ground rent and service charges, council tax or utility bills you pay during void periods, and the cost of professional services such as accountancy and legal fees relating to lettings. The replacement of domestic items relief lets you deduct the cost of replacing furniture, white goods, and furnishings, though not the initial purchase when first furnishing a property.

The key distinction HMRC applies is between repairs and improvements. Repairing a leaking roof or repainting is a deductible repair; adding an extension or upgrading to a materially better standard is a capital improvement, which is not deductible against rental income but may reduce capital gains tax when you eventually sell. New landlords frequently misclassify a renovation as a repair, so keep clear records and photographs of work carried out.

How Do the Section 24 Mortgage Interest Rules Affect You?

Mortgage interest is no longer deductible as a rental expense; instead a landlord receives a basic-rate tax credit worth 20% of their finance costs under the Section 24 rules. This change, fully in force since April 2020, is the single most important rule for any new landlord with a mortgage to understand.

Before Section 24, landlords deducted mortgage interest from rental income before calculating tax. Now, finance costs (mortgage interest, interest on loans to buy furnishings, and related fees) are removed from the expense calculation entirely. Instead, the tax otherwise due is reduced by a credit equal to 20% of those finance costs. For a basic-rate taxpayer the effect is broadly neutral, but for a higher-rate taxpayer the relief is restricted to 20% rather than the 40% they would once have enjoyed.

A consequence many first-time landlords miss is that gross rental income, not net profit, is added to their total income when working out which tax band applies. A landlord on the edge of the higher-rate threshold can be pushed into it by the gross rent, increasing the tax on their other income too. For a fuller treatment of this rule, including incorporation as a planning response, professional advice early in your letting career is worthwhile.

What Does Making Tax Digital Mean for New Landlords?

Making Tax Digital for Income Tax (MTD for IT) requires landlords with qualifying property income above £50,000 to keep digital records and submit quarterly updates to HMRC, with a final declaration due by 31 January. The regime is live from 6 April 2026, so new landlords must check whether they fall within it from the outset.

Qualifying income is measured on gross rental and trading turnover, not profit. Landlords above £50,000 join MTD from 6 April 2026; those above £30,000 join from April 2027; and those above £20,000 join from April 2028. If your property income sits below £20,000, you remain on the existing Self Assessment system for now, filing a single annual return by 31 January.

For landlords within MTD, the practical impact is significant. You must use compatible software to record income and expenses as you go, submit a summary every quarter, and finalise the year with a declaration replacing the old annual return. Setting up digital record-keeping from your first month of letting is far easier than reconstructing it later. A new landlord starting buy-to-let with rents above £50,000, perhaps across two or three properties, should adopt MTD-compatible software immediately rather than relying on spreadsheets.

Until qualifying income crosses the threshold, a new landlord's filing obligation remains the annual return covered in our guide to the landlord's self-assessment return.

Worked Example: What Tax Does a New Higher-Rate Landlord Pay?

A higher-rate landlord receiving £14,400 in annual rent, with £2,400 of allowable expenses and £6,000 of mortgage interest, pays £2,160 in income tax on the property after applying the Section 24 finance cost credit. The example shows how the rules combine in practice.

Consider a first-time landlord who is already a higher-rate taxpayer through their employment. They let a flat for £1,200 a month, giving annual rent of £14,400. Allowable expenses (letting agent fees, insurance, repairs, and service charges) total £2,400. Mortgage interest for the year is £6,000.

Rental profit for tax is calculated as £14,400 income less £2,400 expenses, which is £12,000. Note that the £6,000 mortgage interest is excluded from this calculation. At the higher rate of 40%, the tax on £12,000 is £4,800. The landlord then receives a finance cost tax credit of 20% of £6,000, which is £1,200. The final income tax due on the property is £4,800 less £1,200, which is £3,600.

Had the same landlord been able to deduct the interest in full, as under the old rules, taxable profit would have been £6,000 and the tax £2,400. The difference of £1,200 is the real cost of Section 24 for a higher-rate landlord, and it explains why structuring advice matters from day one.

Frequently Asked Questions

Do I need to tell HMRC if I rent out a property?

Yes. If your rental income exceeds £1,000 in a tax year, you must notify HMRC and register for Self Assessment by 5 October following the end of that tax year. You then file a tax return declaring the income by the following 31 January. Failing to notify HMRC on time can result in a penalty calculated as a percentage of the tax you owe.

How much tax does a new landlord pay on rental income?

A new landlord pays income tax on rental profit at their marginal rate, which is 20%, 40%, or 45% in 2026/27, depending on total income. Profit is rental income minus allowable expenses such as agent fees, insurance, and repairs. Mortgage interest is not deductible but attracts a 20% tax credit. The first £1,000 of rental income is covered by the property allowance and need not be declared.

Can I deduct my buy-to-let mortgage from rental income?

No. Since April 2020, mortgage interest cannot be deducted as a rental expense. Instead, landlords receive a basic-rate tax credit worth 20% of their finance costs under the Section 24 rules. For basic-rate taxpayers the effect is broadly neutral, but higher- and additional-rate landlords receive relief at only 20% rather than their marginal rate, increasing their effective tax bill.

What expenses can a first-time landlord claim?

A first-time landlord can claim expenses incurred wholly and exclusively for letting, including letting agent and management fees, repairs and maintenance, landlord insurance, ground rent, service charges, accountancy fees, and utility or council tax costs during void periods. Replacing domestic furnishings qualifies under replacement of domestic items relief. Improvements and the initial purchase of furniture are capital costs and are not deductible against rental income.

Does Making Tax Digital apply to new landlords in 2026/27?

Making Tax Digital for Income Tax applies to landlords with qualifying property income above £50,000 from 6 April 2026. Those above £30,000 join from April 2027 and those above £20,000 from April 2028. Affected landlords must keep digital records, submit quarterly updates, and file a final declaration by 31 January. Landlords below £20,000 continue with the standard annual Self Assessment return.

What is the £1,000 property allowance?

The property allowance gives every individual £1,000 of tax-free property income a year in 2026/27. If your gross rental income is £1,000 or less, you do not need to declare it or register with HMRC. Above £1,000, you can either deduct the allowance instead of actual expenses or claim your real costs, whichever produces the lower taxable profit. Most landlords with a mortgage benefit from claiming actual expenses.

How Blue Tick Can Help

Your first year as a landlord sets the pattern for every return that follows, and small errors in registration, expense classification, or Section 24 treatment can prove costly. Blue Tick Accountants helps first-time landlords register correctly with HMRC, claim every allowable expense, set up Making Tax Digital record-keeping, and structure their letting in the most tax-efficient way. Head to our website and book a meeting now.

Conclusion

Letting a property for the first time brings real tax obligations, but they are manageable once you understand the framework. Register with HMRC promptly, keep meticulous records of income and expenses, remember that mortgage interest now gives only a 20% credit, and check whether Making Tax Digital applies to you from day one. Getting these foundations right in year one protects you from penalties and ensures you never pay more tax than you need to.

About the Author

This guide was written by Leon, founder of Blue Tick Accountants, a Guildford-based UK tax advisory and accountancy practice that helps landlords, limited company owners and the self-employed across the UK. It was last reviewed for the 2026/27 tax year.

This article is intended for general informational purposes only and does not constitute tax, legal, or financial advice. Tax rules are subject to change and their application will depend on your individual circumstances. You should always seek advice from a qualified professional before taking action. Blue Tick Accountants accepts no liability for decisions made on the basis of this content.