How landlord accounting works is one of those things nobody really explains until you’re already in the middle of it, staring at a folder of receipts and wondering if you’ve been doing something wrong for the past two years. You probably haven’t. But let’s make sure.

What Does Landlord Accounting Actually Involve?

At its core, landlord accounting means keeping a clear record of your rental income and your allowable expenses, then reporting that to HMRC each year through a Self Assessment tax return. That’s it. It doesn’t need to be complicated, but it does need to be done properly. HMRC’s guidance on landlord reporting is clear that rental income must be declared, even if your profits are small or your mortgage absorbs most of the rent.

According to HMRC’s property rental income statistics, there were 2.88 million unincorporated landlords in the UK who declared rental income in 2024 to 2025. Of those, 88% claimed some form of expenses. If you’re not claiming everything you’re entitled to, you’re very likely paying more tax than you should.

What Expenses Can Landlords Actually Claim?

This is where most landlords leave money on the table. Allowable expenses include letting agent fees, property repairs and maintenance, buildings and contents insurance, accountancy fees, ground rent and service charges, and any costs directly related to managing the property. Repairs are claimable. Improvements, such as adding a new bathroom where there wasn’t one before, are not. That distinction catches a lot of people out.

One thing that still surprises landlords is the mortgage interest rule. Since April 2020, you can no longer deduct mortgage interest as an expense in the traditional sense. Instead, you get a basic rate tax credit of 20% on your interest payments. If you pay higher rate tax, this means your taxable profit can look much higher than your actual cash position. The NRLA’s overview of common landlord tax mistakes covers this in more detail, and it’s worth reading if you’re newer to property income.

Self Assessment: What Landlords Need to File and When

If you receive rental income, you almost certainly need to file a Self Assessment tax return by 31 January each year for the previous tax year. A lot of landlords don’t realise this applies to them, particularly if they’re employed under PAYE and see income tax as something their employer sorts out. It doesn’t work that way once rental income is in the picture. HMRC’s enforcement has increased significantly, with landlords paying a combined £107 million in unpaid tax in 2024 to 2025, averaging more than £13,500 per landlord, according to the NRLA.

Penalties for errors range from 0% to 35% of tax due, depending on whether HMRC considers the mistake careless or deliberate. Getting your return filed on time and accurately isn’t just about ticking a box. It’s about protecting yourself from a bill that could be a lot bigger than the tax itself.

Making Tax Digital: What’s Coming for Landlords

Making Tax Digital for Income Tax (MTD for IT) is a change in the way landlords report income to HMRC. Instead of one annual tax return, you’ll use compatible software to send quarterly updates throughout the year. According to GOV.UK, landlords with qualifying income over £50,000 must use MTD from April 2026. Those with income over £30,000 follow in April 2027, and those over £20,000 in April 2028.

The software itself needs to create and store digital records, send quarterly updates to HMRC and submit your final return by 31 January. I’m already helping clients prepare for this using QuickBooks, FreeAgent and Xero, so if MTD is on your radar, it’s a good idea to get set up properly before the deadline rather than scrambling when it arrives.