Registering for Self Assessment

Key facts

You must register for Self Assessment if your gross rental income exceeds £1,000 in a tax year.
Register by 5 October following the end of the tax year in which you first received rental income.
HMRC will post your Unique Taxpayer Reference (UTR) within 10 working days (21 days if overseas).
You can register online at GOV.UK using form SA1 or via your Government Gateway account.
Your first Self Assessment return is due by 31 January following the end of the tax year.

Who Must Register?

You must register for Self Assessment with HMRC if you are a UK landlord and your gross rental income exceeds £1,000 in a tax year. This applies even if your allowable expenses mean you make no profit.^[1]

You do not need to register if:

Your total property income is £1,000 or less (covered by the property income allowance)
Your only rental income is from the Rent-a-Room Scheme and is £7,500 or less

When to Register

You must register by 5 October following the end of the tax year in which you first received rental income. For example:^[1]

First Rental Income Received	Tax Year	Registration Deadline
September 2025	2025/26	5 October 2026
February 2026	2025/26	5 October 2026
May 2026	2026/27	5 October 2027

Tip: Register as soon as you start letting rather than waiting for the deadline. This gives you plenty of time to receive your UTR and set up online access before your first return is due.

How to Register: Step by Step

Go to GOV.UK and search for “register for Self Assessment” or visit the registration page directly.^[1]
Select the reason: Choose “You are a landlord” or “You have income from UK property”.
Complete form SA1: You will need your full name, National Insurance number, date of birth, address, and the date you started receiving rental income.
Submit the form online (or post it to HMRC if you prefer a paper form).
Receive your UTR: HMRC will send your 10-digit Unique Taxpayer Reference by post within 10 working days (21 days if you are overseas).
Create a Government Gateway account: Use your UTR to register for the HMRC online service, where you can file your return.
Enrol for Self Assessment online: Once your Government Gateway account is set up, add Self Assessment as a service. HMRC will post an activation code within 10 working days.

Already Registered for Self Assessment?

If you already file Self Assessment returns (e.g. because you are self-employed), you do not need to register again. Simply add the SA105 property pages to your existing return. You can do this when filing online by selecting “UK property income” as one of your income sources.^[2]

Filing Deadlines

Deadline	Action
5 October	Register for Self Assessment (if newly letting)
31 October	Deadline for paper tax returns
31 January	Deadline for online tax returns and tax payment
31 July	Second payment on account (if applicable)

Penalties for Late Registration and Filing

If you fail to register or file on time, HMRC can charge penalties:^[2]

£100 automatic penalty for a return up to 3 months late
£10 per day for the next 3 months (up to £900)
Further penalties of 5% of the tax due at 6 and 12 months late
Interest on any unpaid tax from the due date

Already letting but never registered? Contact HMRC as soon as possible. Voluntary disclosure is treated more favourably than being discovered during an investigation. HMRC’s Let Property Campaign allows landlords to regularise their affairs with reduced penalties.

Frequently Asked Questions

Do I need to register if I only earn a small amount of rent?

If your gross rental income is £1,000 or less, the property income allowance covers it and you do not need to register or report it. If your income exceeds £1,000, you must register for Self Assessment even if your expenses mean you make no profit.

How do I register for Self Assessment as a landlord?

Register online at GOV.UK using form SA1. You will need your National Insurance number, your address, and details of when you started receiving rental income. HMRC will send your UTR by post within 10 working days.

What is a UTR and why do I need one?

A Unique Taxpayer Reference (UTR) is a 10-digit number HMRC uses to identify your tax affairs. You need it to file your Self Assessment return online and to set up your Government Gateway account for submitting returns.

What happens if I register late?

Late registration can lead to late filing penalties. If your return is late, HMRC charges an automatic £100 penalty, with further penalties accumulating over time. If you have underpaid tax, interest will also be charged.

Sources

Register for Self Assessment — GOV.UK
Self Assessment tax returns — GOV.UK
Property income: tax return notes — GOV.UK

Registering for Self Assessment as a Landlord