Discover how to file your taxes correctly with self-assessment tips for UK residents and non-residents
Each year, millions of people complete their personal tax returns through HMRC’s Self-Assessment system. It’s how HMRC collects tax on income that hasn’t already been taxed at source – for example, from self-employment, rental property, investments, or overseas earnings.
If you’re UK resident, Self-Assessment helps you report all your income and claim tax reliefs. If you’re non-UK resident, you may still need to file a return if you receive UK income, such as rent from UK property or employment income not fully taxed under PAYE.
Filing correctly and on time can help you avoid penalties, overpayments, and unnecessary stress.
Who Needs to File a UK Self-Assessment Tax Return?
You’ll usually need to file if you are:
UK Resident and…
- Self-employed (sole trader) earning more than £1,000
- A partner in a business partnership
- Receiving income from property rental
- Earning savings or investment income over £10,000 before tax
- Receiving untaxed income (e.g. tips or commission)
- Foreign income
- Claiming Child Benefit while you/your partner earn over £50,000 (High Income Child Benefit Charge applies)
- A company director whose income isn’t fully taxed through PAYE
- Liable to Capital Gains Tax on sales of property, shares, or other assets
Non-UK Resident and…
- Receiving UK rental income (directly or through the Non-Resident Landlord Scheme)
- A partner in a UK business partnership
- Selling UK property or land (Capital Gains Tax rules apply to non-residents)
- Receiving savings or employment income not fully taxed through PAYE
- Claiming reliefs under the Statutory Residence Test or a double taxation treaty
If unsure, you can use HMRC’s online checker or seek professional advice. Correctly establishing your tax residence status is critical.
Registering for Self-Assessment
- Deadline: Register by 5 October following the end of the tax year if it’s your first time filing.
- Process: HMRC will issue a Unique Taxpayer Reference (UTR) which you’ll use each year to file your return.
- Tip for non-residents: Allow extra time for HMRC correspondence to be sent overseas addresses.
Filing Your Tax Return Online
Filing online is the fastest and most secure option. You’ll need your Government Gateway ID, password, and UTR.
Steps:
- Log into your personal tax account at HMRC.
- Select “Self Assessment” and choose the tax year.
- Enter all relevant income – including employment, rental, investments, and overseas income (if resident).
- Add allowable expenses and tax reliefs.
- Check HMRC’s calculation summary.
- Submit and keep the confirmation reference.
- Pay any tax due by 31 January (and 31 July if payments on account apply).
For non-residents, it’s important to:
- Confirm your residence status for the year.
- Claim double tax treaty relief if eligible.
- Declare only UK-sourced income: Note that “disregarded income” is not taxable in the UK.
Disregarded income typically refers to certain types of UK income that non-residents receive, such as UK bank or building society interest, National Savings income, dividends, or some pension income. While it must often still be reported on your return, HMRC does not tax it for non-residents.
This means you won’t pay UK tax on it, though you may need to consider tax in your country of residence.
Common Mistakes to Avoid
- Missing the registration deadline.
- Forgetting to declare rental or overseas income.
- Misapplying residence rules or double tax reliefs.
- Guessing figures instead of using official records.
- Claiming ineligible expenses (e.g. private travel or home costs).
Deadlines & Penalties
- Paper returns: 31 October after the tax year ends.
- Online returns: 31 January after the tax year ends.
- First registration: 5 October after the end of the relevant tax year.
- Payments: 31 January (and 31 July for payments on account).
Penalties:
- £100 if return is up to 3 months late.
- Daily penalties and interest if filing/payment is delayed further.
Do You Need an Accountant?
Self-Assessment is designed to be user-friendly, but professional advice can be valuable if you:
- Have multiple income sources.
- Are declaring UK and overseas income.
- Need to apply the Statutory Residence Test.
- Are claiming double taxation treaty relief.
- Are reporting capital gains or crypto assets.
Even a one-off review can provide peace of mind and ensure you don’t pay more tax than necessary.
How PKF BBA Can Help
We assist both UK residents and non-UK residents with:
- Preparing and filing UK Self-Assessment tax returns.
- Completing non-resident landlord returns (individuals and companies).
- Advising on UK tax residence rules and the Statutory Residence Test.
- Applying double taxation treaty reliefs.
- Helping families manage tax when leaving, returning, or splitting time in the UK.
We are experts in understanding and applying the UK Tax Residence Rules and helping individuals understand the Statutory Residence Test and how it may apply to them. We speak directly with you and your family to understand what you’re aiming to achieve, whether you’re leaving the UK, returning, or spending part of the year abroad.
If you’d like to discuss your situation, please contact: Garry Bell, Head of Tax, Kerry Emblem, Private Client Tax Director, or Anthony Chandlen, Tax Director.