Moving abroad is exciting, but leaving the UK without sorting your tax affairs can lead to overpaid tax, missed refunds, and unwanted penalties from HMRC.
Many people focus on flights, visas, and packing but forget about their UK tax obligations until it is too late.
By then, they have closed their bank account, lost their P45, or missed a claim deadline.
This UK expat tax checklist gives you 10 practical steps to complete before you leave.
Follow them in order and you will leave the UK with your tax affairs settled, your refund claimed, and no surprises from HMRC after you have gone.
Key Takeaways
- Sort your UK tax before you leave—it is much harder to resolve from overseas
- Collect your P45 from your last employer before departing
- Keep your UK bank account open until you receive any refund from HMRC
- Tell HMRC you are leaving using form P85 or your Self Assessment tax return
- Check whether split year treatment applies to reduce your UK tax bill
- You have four tax years to claim overpaid tax, but acting before you leave is simplest
Step 1: Get Your P45 From Your Last Employer
Your P45 is the single most important tax document when leaving the UK. It records your earnings and the tax deducted in the current tax year.
What to do:
- Ask your employer for your P45 on or before your last working day
- You will receive Parts 1A, 2, and 3
- Keep Part 1A for your own records
- Parts 2 and 3 go to HMRC with your P85 claim
If your employer delays:
- Chase them promptly—employers must issue a P45 when you leave
- If the P45 does not arrive before you depart, ask your employer to post it to your new overseas address
- As a backup, request a written statement of earnings on company letterhead showing your gross pay and tax deducted
Your P45 significantly speeds up any refund claim. Without it, HMRC can still process your claim but it will take considerably longer.
Step 2: Gather Your Tax Documents
Before you leave, collect and photocopy every tax-related document you may need. Tracking down paperwork from overseas is difficult and time-consuming.
Documents to gather:
- P45 from your current or last employer
- P60s from previous tax years (if claiming for earlier years)
- Payslips from the current tax year
- Your National Insurance number (check payslips, P60, or HMRC letters)
- Records of any work expenses you have not yet claimed (uniforms, tools, professional fees, mileage)
- Details of any UK pensions you hold
- Records of UK property you own or rent out
- Any correspondence from HMRC (tax code notices, P800 calculations)
Storage tip:
Scan or photograph everything and save digital copies in cloud storage. Paper documents can be lost in transit and some HMRC forms cannot be replaced.
Step 3: Check Whether You Are Owed Tax Back for Work Expenses
Many people leave the UK without realising they could claim tax relief on employment expenses from the years they worked here.
Common unclaimed expenses:
- Uniform washing and maintenance (flat rate allowances vary by industry)
- Tools and equipment bought for work
- Professional body and trade union subscriptions
- Mileage for using your own vehicle for business journeys (not commuting)
How to claim:
- If you have not yet left, submit form P87 to HMRC or claim online
- If you file Self Assessment, include expenses on your tax return
- You can claim for the current year plus the previous four tax years
Work expense claims are handled separately from your P85 leaving claim. Submitting both maximises what you receive back.
Check our guides on uniform tax refunds, mileage allowance tax relief, and tool tax relief to see what applies to your profession.
Step 4: Keep Your UK Bank Account Open
This step catches out more people than any other on this list. If you close your UK bank account before receiving your tax refund, getting paid becomes extremely complicated.
Why this matters:
- HMRC currently only issues P85 refunds by cheque in pounds sterling
- They cannot transfer to overseas bank accounts
- Overseas banks often refuse to cash sterling cheques or charge high fees
- If your UK account is closed when the cheque arrives, you may need to arrange a nominee in the UK
What to do:
- Keep your UK bank account open for at least 3-4 months after submitting your P85
- Check whether your bank allows you to maintain the account from overseas (most do, though some require a UK address)
- Set up mobile banking and cheque deposit via app if available
- Once your refund is deposited, you can transfer the funds overseas and then close the account
If you absolutely must close your account before leaving, nominate a trusted person in the UK to receive the cheque on your behalf. You can specify a nominee on form P85.
Step 5: Tell HMRC You Are Leaving the UK
Notifying HMRC is essential. If you do not, they may continue treating you as UK resident and expect tax on income you earn overseas.
Which form to use:
- Form P85 – Use this if you do not file Self Assessment tax returns. It tells HMRC you are leaving and claims any overpaid tax in one step.
- Self Assessment tax return with SA109 – Use this if you already file Self Assessment. The SA109 residence pages capture your departure details and claim split year treatment if applicable.
When to submit:
- You can submit form P85 before you leave (postal only) or after you leave (online or postal)
- If submitting before departure, print the form from gov.uk and post it with your P45
- If submitting after departure, using the online Government Gateway service is often the easiest way.
What the form asks:
- Your departure date and reason for leaving
- Whether you are leaving permanently or for a fixed period
- Your new overseas address
- Details of any UK income you will continue to receive
- Your employment details and P45 information
- How you want to receive any refund
Answer every question accurately. Incomplete forms cause delays and may affect how HMRC determines your residence status.
Step 6: Check Whether Split Year Treatment Applies
Split year treatment can reduce your UK tax bill in the year you leave. Understanding whether it applies to you is worth checking before you go.
What it does:
Split year treatment divides the tax year into a UK resident part and an overseas part. During the overseas part, you are only taxed on UK-source income rather than your worldwide income.
You may qualify if you are:
- Starting full-time work overseas (35+ hours per week) for at least one complete tax year, and you spend fewer than 91 days in the UK after leaving with fewer than 31 UK workdays
- Accompanying a spouse or partner who qualifies under the work abroad rule
- Permanently giving up your UK home, with fewer than 16 days spent in the UK afterwards, and establishing a home overseas within 6 months
Why it matters:
If you start earning overseas income shortly after leaving, split year treatment ensures that income is not taxed in the UK.
Without it, you could be taxed on worldwide income for the entire year even though you only lived in the UK for part of it.
How to claim:
If you file Self Assessment, claim split year treatment on form SA109. If you use form P85, the information you provide helps HMRC decide whether it applies.
Keep records of your departure date, overseas employment start date, and UK visits.
Read our full split year treatment guide detailed qualifying conditions.
Step 7: Deal With UK Property Before You Go
If you own UK property that you plan to keep and rent out, there are specific steps to take before leaving.
Becoming a non-resident landlord:
Once you leave the UK, HMRC classifies you as a non-resident landlord. This triggers specific obligations:
- Your letting agent or tenant must deduct 20% basic rate tax from your rent under the Non-Resident Landlord Scheme
- You can apply to receive rent without tax deducted by completing form NRL1 (HMRC approval required)
- You must register for Self Assessment and file annual UK tax returns
- Allowable expenses such as mortgage interest relief, repairs, and insurance can be claimed on your tax return
If you are selling UK property:
- Try to complete the sale before you leave if possible
- Non-residents pay Capital Gains Tax on UK property sales at 18% (basic rate) or 24% (higher rate)
- You must report the sale and pay CGT within 60 days of completion
- The annual CGT exemption is just £3,000 for 2025/26
Action before leaving:
- Inform your letting agent of your non-resident status
- Apply for NRL1 approval if you want to receive rent gross
- Register for Self Assessment (form SA1) if not already registered
- Keep records of all property expenses for your tax returns
See our guide on letting UK property when living abroad for the full requirements.
Step 8: Review Your UK Pension Position
Your UK pension does not disappear when you leave. Understanding how it is treated from overseas saves confusion later.
State Pension:
- Your entitlement is based on your National Insurance contribution record
- You need 35 qualifying years for the full State Pension
- Check your NI record at gov.uk to see how many years you have
- You can pay voluntary Class 3 NI contributions (£17.45 per week in 2025/26) while abroad to fill gaps
- You have up to 6 years to fill NI gaps retrospectively
Workplace and private pensions:
- Existing UK pensions remain invested and grow while you are overseas
- You do not need to transfer them out of the UK
- When you eventually draw from them, the tax treatment depends on the double taxation treaty between the UK and your country of residence
National Insurance contributions:
You cannot claim back NI contributions already paid. Your UK contributions may count toward benefits in your new country if a social security agreement exists.
Countries with agreements include all EU/EEA nations, the USA, Canada, Australia, and many others.
Step 9: Set Up Mail Forwarding and Update Your Address
HMRC and other organisations will continue sending important correspondence to your last known UK address. Missing these letters can cause problems.
Essential address updates:
- HMRC – your P85 provides your new address, but also update your Personal Tax Account at gov.uk
- Your bank – update to ensure statements and cheques reach you
- Your pension providers – workplace and private pensions
- Your former employer – in case they need to send amended P45 or other documents
- DVLA – if you hold a UK driving licence
- Your local council – to stop Council Tax charges
Mail forwarding:
- Set up Royal Mail redirection for at least 6-12 months
- This catches any HMRC letters, bank correspondence, or other important post
- Redirection costs vary depending on duration and can be set up online at royalmail.com
Digital access:
- Set up or check your HMRC Personal Tax Account before leaving
- Ensure your Government Gateway login details are saved
- This allows you to check your tax position, track refund claims, and respond to HMRC queries from overseas
Step 10: Note Your Deadlines and Set Reminders
Once you leave the UK, it is easy to forget about UK tax deadlines. Missing them can mean lost refunds or unexpected penalties.
Key deadlines to remember:
- Four-year claim limit – You can claim overpaid tax for the current year plus the previous four tax years. After that, the money is lost permanently.
- Self Assessment filing – If you need to file a UK tax return, the deadline is 31 January following the end of the tax year
- CGT reporting – If you sell UK property, you must report and pay within 60 days of completion
- P800 refunds – Since May 2024, HMRC no longer automatically sends refund cheques for P800 overpayments. You must actively claim online.
Practical tips:
- Set calendar reminders for January 31 each year if you file Self Assessment
- Check your HMRC Personal Tax Account periodically for P800 notifications
- Keep digital copies of all tax documents accessible from overseas
- Consider appointing a UK-based tax agent to handle your affairs if you have ongoing UK income
Quick Reference: Your Departure Tax Checklist
Use this summary to check off each step:
- Collected P45 from last employer
- Gathered and scanned all tax documents
- Checked and claimed any outstanding work expense relief
- UK bank account kept open (minimum 3-4 months after P85 submission)
- Submitted form P85 to HMRC (or SA109 if Self Assessment)
- Checked split year treatment eligibility
- Dealt with UK property (NRL registration, NRL1, Self Assessment)
- Reviewed pension position and NI record
- Set up mail forwarding and updated addresses
- Noted deadlines and set reminders
UK Expat Checklist FAQ’s
Q1: When should I submit form P85 to HMRC?
A: You can submit form P85 before or after leaving the UK. If submitting before departure, you must use the postal version. If submitting after you have left, you can complete it online through your Government Gateway account. Submitting before you leave is often simpler because you still have easy access to documents and your UK bank account.
Q2: Do I need to pay tax in the UK after I leave?
A: It depends on whether you have UK income sources. If you have UK rental property, a UK pension, or other UK-source income, you may still need to pay UK tax and file annual Self Assessment returns. If you have no UK income after leaving, you should not owe further UK tax once your P85 is processed.
Q3: How do I check my National Insurance record before leaving?
A: You can check your NI record online through your Personal Tax Account at gov.uk. This shows how many qualifying years you have toward your State Pension and highlights any gaps. You can pay voluntary contributions to fill gaps even after leaving the UK.
Q4: What happens if I forget to tell HMRC I am leaving?
A: If you do not notify HMRC, they may continue treating you as UK resident and expect tax on worldwide income. They may also continue issuing tax codes to employers. Filing a P85 or SA109 updates your record and triggers any refund you are owed. You can still notify HMRC after you have left.
Q5: Can I claim tax back for previous years when I leave?
A: Yes, you can claim overpaid tax for the current year plus the previous four complete tax years. This includes work expenses you never claimed such as uniform allowances, tool costs, and professional subscriptions. The four-year limit is strict so check your eligibility before the deadline passes.
