In this guide, we’ll cover what landlords need to include on a tax return, key deadlines, allowable expenses, and how to make the process easier.

You need to complete a Self Assessment tax return if you earn income from property. That includes:

• Renting out a residential or commercial property in the UK.
• Letting out a room in your own home (see Rent-A-Room below).
• Earning income from overseas property.
• Holiday lets, including Airbnb properties.

The key tax return deadlines for landlords are:

• 5 October - register for Self Assessment if this is your first year as a landlord (don't panic if you've missed it this year, just register as soon as you can).
• 31 October - paper tax return filing deadline (rarely used).
• 31 January - online tax return and payment deadline for the previous tax year.

For example, for the 2024/25 tax year (ending 5 April 2025), your tax return and any tax owed must be submitted by 31 January 2026.

Missing these deadlines can result in automatic penalties and interest, even if you owe no tax.

You’ll need to declare all rental income, including:

• Monthly rent payments.
• Any non-refundable deposits kept.
• Income from additional services (e.g. cleaning or parking).

HMRC expects full disclosure, so it’s important to maintain accurate records of all property income and related costs throughout the year.

Claiming allowable expenses reduces your taxable profit - and therefore your tax bill. Common allowable expenses include:

• Letting agent fees
• Accountancy fees
• Repairs and maintenance (not improvements)
• Insurance
• Council tax, utilities, and service charges (if paid by you)
• Advertising and tenant reference checks
  

You can also claim a 20% tax relief on mortgage interest paid.

Make sure you keep receipts and records for at least six years in case HMRC asks for evidence.

Details of improvements made should be kept for the future as it may be able to claimed when you sell the property.

If you rent a room in your house where the tenants share facilities with you, you may be able to claim rent-a-room relief. For 2024/25 it's up to £7,500 of gross rental income, or £3,750 each if the income is joint. Any income in excess of this is taxable.

Making Tax Digital for Income Tax is due to affect landlords from April 2026.

If your gross rental income exceeds £50,000, you’ll need to:

• Keep digital records of property income and expenses.
• Submit quarterly updates to HMRC.
• File a final year-end declaration digitally.

Landlords earning between £30,000-£50,000 will follow in April 2027, and £20,000-£30,000 in April 2028.

Getting used to digital record-keeping now will make the transition much smoother.

Yes - and increasingly easily. HMRC use data from letting agents, Airbnb, the Land Registry, mortgage providers, and even online platforms to identify landlords who haven’t declared rental income.

HMRC can go back several years, charge penalties and interest, and in some cases issue higher fines for deliberate non-disclosure. However, if you come forward voluntarily before HMRC contacts you, you’ll usually receive lower penalties and can settle the tax owed under more favourable terms.

If you’re unsure whether you’ve declared everything correctly, it’s always best to get professional advice before HMRC does.

Don't forget to double check who owns the property (there are often cases where one person in a couple has declared all income even though it's jointly owned). People also often mistakenly think they don't need to declare because their mortgage payment means they have no profit, but as it's only a 20% tax relief on the interest, not the whole repayment, there can be a taxable profit.

Completing your own tax return can be time-consuming and confusing - especially with changing tax rules. Here are a few ways to simplify the process:

• Track income and expenses monthly instead of leaving it until the end of the year.
• Use accounting software that’s MTD-compatible.
• Get professional help - an accountant can identify allowable expenses, ensure accuracy, and help you plan ahead for tax changes.

At CJL Accountancy, we make tax simple.

Whether you’re a first-time landlord or managing multiple properties, we’ll handle your Self Assessment, bookkeeping, and tax planning - ensuring you stay compliant and never pay more tax than you should.

📞 Get in touch to find out how we can help make your landlord accounting stress-free.