Registering with HMRC as a landlord: a 2026 guide | August

Registering with HMRC as a landlord: when, how and the deadlines that matter

If you earn rental income from UK property above £1,000 a year, you generally have to tell HMRC and register for Self Assessment, and the deadline to do it is 5 October following the tax year in which the income arose. Miss it and penalties can follow; get it right and the process is straightforward. This guide explains exactly when a landlord needs to register, how to do it step by step, the deadlines and forms that apply afterwards, and how Making Tax Digital for Income Tax, now live for higher-earning landlords, changes what you need to keep and submit.

When do you need to register with HMRC?

Whether you need to register depends on how much rent you receive, not on how many properties you own or whether letting is your main job.

The starting point is the property allowance, a £1,000 tax-free allowance for property income introduced by the Finance (No. 2) Act 2017. If your gross rental income for the tax year is £1,000 or less, that income is exempt and you do not need to report it or file a return for it. As HMRC sets out on gov.uk, once your gross rental income goes above £1,000 you need to tell HMRC, and in almost all cases that means registering for Self Assessment and filing an annual return. The allowance is per person rather than per property, so a landlord with five properties still has a single £1,000 allowance, while joint owners each have their own against their share of the income. You claim either the £1,000 allowance or your actual allowable expenses, whichever leaves you better off, but not both, and for most mortgaged buy-to-let landlords actual expenses will be the larger figure.

Where rental income is only a little above the allowance, HMRC can sometimes collect the tax by adjusting your PAYE tax code rather than asking for a full return, so if you are close to the line it is worth running HMRC's "Check if you need to send a Self Assessment tax return" tool before assuming either way. If you let more than one property, HMRC treats you as running a rental business, which makes a return the norm. Accidental landlords, people who inherited a property or moved in with a partner and let their old home, are caught by exactly the same rules, and our checklist for accidental landlords walks through the first steps.

The registration deadline is 5 October following the end of the tax year in which you first received rental income, a date confirmed in HMRC's Self Assessment guidance. If you started letting during the 2025/26 tax year, which ran to 5 April 2026, you must register by 5 October 2026. Missing the deadline does not change the obligation; register as soon as you can, because penalties are generally lighter when you come forward voluntarily than when HMRC contacts you first.

How HMRC tracks rental income

Landlords often wonder how HMRC would ever know about undeclared rent. In practice it has several routes. Every purchase generates a Stamp Duty Land Tax record, and HM Land Registry data shows who owns what in England and Wales, so a person holding several residential properties stands out. Letting agents are required to keep detailed financial records that HMRC can request, and tenants, neighbours or former partners sometimes report undeclared lettings directly. HMRC also cross-references the electoral roll and other data held against your National Insurance number.

For landlords who have not declared income they should have, HMRC runs the Let Property Campaign, a voluntary disclosure route with more favourable terms than being found during an investigation. Coming forward through it almost always produces a lower penalty than waiting to be caught.

How to register, step by step

The exact form depends on whether you have other self-employment, but the path is the same.

First, set up a Government Gateway account if you do not already have one, which you can do as part of the registration process on gov.uk. You will need your name, address, date of birth, National Insurance number and contact details. Next, choose the right form. Landlords who are also self-employed use the CWF1, which registers them for Self Assessment and Class 2 National Insurance together. Landlords with no other self-employment, including those with a job alongside their rental income, use the SA1, the Self Assessment registration for people who are not self-employed. Both can be completed online.

The form asks for your personal details, information about your rental properties, your expected income and whether you let jointly with anyone. Be accurate, and complete the joint-ownership sections carefully if you own with a spouse or partner, because each owner declares their own share. After you submit, HMRC sends your ten-digit Unique Taxpayer Reference by post, usually within about ten working days, or longer if you are abroad. You keep the same reference for as long as you are a landlord, however your portfolio changes. HMRC then sends a separate activation code, again by post, which you enter once to activate your online Self Assessment account. Once activated, you can file returns, see what you owe and pay through the same account, and most landlords find online filing quicker and less error-prone than paper.

After you register: deadlines and what to declare

Once registered, you file a Self Assessment return each year covering the tax year from 6 April to 5 April. The dates to hold onto are 31 October for a paper return, 31 January for an online return and for paying the tax you owe, and 31 July for the second payment on account where one applies.

Your rental income goes on the SA105 form, the UK property supplement to the main return, published by HMRC. You declare all rental income, which includes the rent itself, any retained deposit you keep for damage or arrears, and service charges you collect. Against that you set your allowable expenses, the costs that are wholly and exclusively for letting the property, and our guide to allowable expenses for landlords covers what does and does not qualify in detail. The one area that catches landlords out is finance costs: since April 2020 you can no longer deduct mortgage interest as an expense, and instead receive a 20% basic-rate tax credit under Section 24, which particularly affects higher-rate taxpayers.

You pay Income Tax on your rental profit at your marginal rate, with the gain stacked on top of your other income to decide the band, and you do not pay National Insurance on rental income even when you run a property business. The exact bands differ if you are a Scottish taxpayer, and our guide to how rental income is taxed works through the calculation; to get a quick estimate of what a given profit would cost you, the August rental income tax calculator does the arithmetic.

Making Tax Digital for Income Tax

The biggest recent change to landlord reporting is already here. Making Tax Digital for Income Tax has applied since 6 April 2026 to landlords whose qualifying income, meaning gross income from self-employment and property combined, is above £50,000. As HMRC's guidance confirms, the threshold drops to £30,000 from April 2027 and to £20,000 from April 2028, which will eventually bring most landlords in.

Where it applies, MTD replaces the single annual return with digital record-keeping, four quarterly updates summarising income and expenses, and a final declaration after the fourth quarter where you make any adjustments and confirm your tax. You still need to be registered for Self Assessment, and you need software that can submit directly to HMRC. We keep the detail current in the August Making Tax Digital hub, and our step-by-step MTD setup guide walks through connecting a bank account, logging expenses and preparing a first quarterly submission. August supports direct MTD for Income Tax filing, so if your income is above the threshold you can keep the records and make the submissions in one place rather than bolting software onto a spreadsheet.

Common mistakes to avoid

A handful of errors account for most of the penalties landlords face. The first is registering late, or not at all, on the assumption that a small or occasional let does not count; all rental income above the allowance must be declared, however it is paid. The second is claiming costs that are not allowable, such as capital improvements, the initial purchase of furniture or anything personal, when only expenses wholly and exclusively for the letting qualify. The third is poor record-keeping: HMRC can ask for evidence of income and expenses going back several years, so receipts, invoices, bank statements and correspondence all need keeping. Landlords who own jointly sometimes forget that each owner registers and declares their own share separately. And anyone with undeclared income from earlier years should use the Let Property Campaign rather than hope it goes unnoticed.

What happens if you do not register?

The consequences of not registering when you should escalate over time. Late filing brings an automatic £100 penalty, with further daily penalties once a return is more than three months late, and HMRC charges interest on any tax paid late from the date it was due. Beyond that, failing to notify HMRC of taxable income carries its own penalty regime, based on whether the failure was careless or deliberate and on how the disclosure came about, which is why voluntary disclosure through the Let Property Campaign matters: penalties for income HMRC uncovers through an investigation are typically far higher, and in the most serious cases of deliberate evasion HMRC can pursue prosecution. None of this is a reason for alarm if you register and report in good time; it is simply the reason to do so.

Staying on top of it long-term

Once you are registered, the work becomes a routine rather than an annual scramble. Log income and expenses as they happen instead of reconstructing the year each January. Set money aside for the bill as you go, because tax on rental income is not deducted at source; a rough reserve of 20% to 40% of profit depending on your band keeps you covered. Expect payments on account if your bill is over £1,000, which are advance payments toward the next year due on 31 January and 31 July, as gov.uk explains. Review your position each April, since new properties, a change of letting arrangement or rising rents can change your obligations, including whether you have crossed an MTD threshold. If you let a room in your own home rather than a separate property, different rules apply under the Rent a Room scheme, which our guide to taking in a lodger covers, and if you hold or plan to hold property through a company, incorporation changes registration entirely, since a company registers for Corporation Tax rather than Self Assessment.

Keeping clean records year-round is the single thing that makes all of this easier, and it is what August is built for. The August smart reminders keep the 5 October and 31 January deadlines from slipping past, and expense tracking logs the costs that reduce your bill as they arise, so your figures are ready when the return is due.

Frequently asked questions

Do I need to register if I earn under £1,000 in rent? 

No. Gross rental income of £1,000 or less in a tax year is covered by the property allowance, is exempt from Income Tax and does not need to be reported for that income alone. Above £1,000 you need to tell HMRC and will normally register for Self Assessment.

When is the deadline to register? 

You must register by 5 October following the end of the tax year in which you first received rental income. So rental income first received during the 2025/26 tax year means registering by 5 October 2026.

Do I pay National Insurance on rental income? 

No. Rental income is not subject to National Insurance, even where letting amounts to a property business. This is one of the ways it differs from self-employment income.

Do I have to register if my rental made a loss? 

Often yes. Registering and filing lets you record the loss, which can be carried forward against future rental profits, so it is usually worth doing even in a loss-making year. The property allowance, by contrast, cannot create a loss.

Do joint owners register separately? 

Yes. Each owner registers in their own right and declares their share of the income and expenses on their own return. If you would rather keep those records in one place from the start, you can start for free on August.

Final thoughts

Registering with HMRC as a landlord is not complicated once you know the triggers and the dates. Tell HMRC once your rental income passes £1,000, register by the 5 October deadline, file and pay through Self Assessment, and move to digital records under Making Tax Digital if your income is above the threshold. Start early, keep organised records through the year, and the administration stays small. Making Tax Digital is no longer on the horizon; for higher-earning landlords it has already begun, and the ones who set their records up properly now will barely notice the change.

This article is general guidance, not legal, financial or tax advice. Tax rules change and circumstances vary, so always consult a qualified accountant or tax adviser about your own situation. Accurate at the time of writing in 2026.