UK vs Australia: What You Need to Know About Personal Tax When Relocating (2025/26)
Relocating between the UK and Australia is an exciting life change — but it also brings complex tax considerations that are easy to overlook. Getting it wrong can result in unexpected liabilities, penalties, or double taxation. Understanding how each country’s tax system operates before you move is therefore essential.
At AUK Tax, we specialise in helping individuals manage UK–Australia cross-border tax matters. Below is a clear, structured comparison of the key personal tax differences for the 2025/26 tax year.
How Do the UK and Australian Tax Systems Differ?
Although both systems are progressive and both have a top marginal rate of 45%, the similarities largely end there. The two countries differ significantly in their tax year dates, filing requirements, treatment of investment income, capital gains rules, social security systems, and estate taxation.
Understanding these structural differences is crucial when planning a relocation.
What Is the Tax Year in the UK vs Australia?
The tax years do not align.
In the UK, the tax year runs from 6 April to 5 April the following year. In Australia, the tax year runs from 1 July to 30 June.
If you relocate partway through a year, you may find yourself with filing obligations in both countries for overlapping periods. Timing of departure or arrival can materially affect reporting obligations and residency status.
Who Needs to File a Tax Return?
In the UK, most employees are taxed through PAYE (Pay As You Earn) and do not automatically need to file a self-assessment return. However, a return is generally required if you:
Earn over £100,000
Receive overseas income
Have rental or significant investment income
Dispose of assets subject to Capital Gains Tax
Are self-employed
Australia takes a broader approach. Most Australian residents and non-residents with Australian-sourced income are required to lodge a tax return, with only limited exclusions. Filing is therefore far more common in Australia than in the UK.
Tax-Free Allowances and Thresholds (2025/26)
UK residents benefit from a £12,570 personal allowance. However, this allowance tapers once income exceeds £100,000 and is fully withdrawn once income exceeds £125,140.
In Australia, the tax-free threshold is $18,200 — but this applies only to Australian tax residents. Foreign residents are not entitled to this threshold and are taxed from the first dollar of Australian-sourced income.
In the UK, individuals may still be entitled to the UK personal allowance even if they are non-resident for tax purposes, provided certain conditions are met (for example, being a British citizen or meeting other qualifying criteria).
Australia takes a stricter approach. Non-residents of Australia are not entitled to the tax-free threshold and are taxed from the first dollar of Australian-sourced income.
This distinction can have a significant practical impact when relocating from Australia to the UK. It is crucial to determine the exact date you cease to be an Australian tax resident. The timing of departure — especially where you leave close to the end of the Australian tax year on 30 June, a common period for moves ahead of the UK summer — can materially affect how much tax-free income you are entitled to and how your income is assessed in both jurisdictions.
Careful planning around residency status and departure timing can therefore prevent unnecessary tax exposure.
Income Tax Rates: UK vs Australia (2025/26)
United Kingdom (2025/26)
| Taxable Income | Rate |
|---|---|
| Up to £12,570 | 0% |
| £12,571 – £50,270 | 20% |
| £50,271 – £125,140 | 40% |
| Over £125,140 | 45% |
(Scottish taxpayers are subject to different rates.)
Australia (2025/26 – Residents)
| Taxable Income | Rate |
|---|---|
| Up to $18,200 | 0% |
| $18,201 – $45,000 | 16% |
| $45,001 – $135,000 | 30% |
| $135,001 – $190,000 | 37% |
| Over $190,000 | 45% |
Australia’s Stage 3 tax changes (effective 1 July 2024) reduced rates for middle-income earners, making the system more competitive at those levels. These rates apply to Australian residents only.
Capital Gains Tax: How Does It Compare?
The UK provides an annual Capital Gains Tax exemption of £3,000. Gains above this threshold are taxed at:
18% or 24% (depending on income band)
Australia does not offer a separate annual CGT allowance. Instead, Australian residents who hold an asset for at least 12 months receive a 50% discount on the capital gain. The discounted gain is then added to ordinary income and taxed at marginal rates.
This difference often produces very different outcomes depending on income level and holding period.
Dividends: Franking Credits vs the UK System
Australia’s dividend imputation system is one of its most distinctive features.
When an Australian company pays corporate tax and distributes profits, it may attach a franking credit representing tax already paid. Shareholders include the grossed-up dividend in their income but can offset the franking credit against their personal tax liability. If their marginal rate is lower than the corporate tax rate, they may receive a refund.
This can make fully franked dividends highly tax-efficient — particularly for retirees or lower-income investors.
The UK has no equivalent system. Dividends are paid from post-tax profits and are then taxed at the shareholder level. For 2025/26, the UK dividend allowance is £500, after which dividends are taxed at:
8.75% (basic rate)
33.75% (higher rate)
39.35% (additional rate)
There is no credit for underlying corporate tax paid. These tax rates listed above will rise by 2% from 06 April 2026, as detailed in the latest UK budget.
For individuals holding Australian shares — either before or after relocating — understanding franking credits is essential to avoid overpaying tax.
Inheritance Tax: A Major Structural Difference
The UK levies Inheritance Tax at 40% on estates exceeding £325,000. An additional £175,000 residence nil-rate band may apply when passing a family home to direct descendants, subject to tapering for larger estates.
Australia has had no inheritance tax since 1978.
For high-net-worth individuals, this is often one of the most significant structural differences between the two systems and can heavily influence long-term estate planning decisions.
National Insurance vs Medicare and Superannuation
In the UK, employees pay National Insurance contributions at:
8% between £12,570 and £50,270
2% above £50,270
Self-employed individuals in the UK pay a different class (2 and 4) of national insurance, with varying rates.
Australia does not operate a National Insurance equivalent. Instead, residents pay a Medicare levy of 2% of taxable income, with a potential surcharge (up to 1.5%) for higher earners without appropriate private health cover.
Employers must also contribute to Superannuation at 11.5%, rising to 12% from 1 July 2025.
The overall cost structure between the two systems can therefore differ materially.
Tax Return Deadlines
In the UK, online self-assessment returns must be filed by 31 January following the end of the tax year. For the year ending 5 April 2026, the deadline is 31 January 2027.
In Australia, the standard lodgement deadline is 31 October following the 30 June year-end. Individuals registered with a tax agent generally receive an extension to 15 May of the following year, subject to ATO conditions.
Worldwide Income and Residency
Both countries tax residents on worldwide income.
The UK introduced a new residence-based regime from 6 April 2025, replacing the previous remittance basis for new arrivals. Australia taxes residents on global income, while foreign and temporary residents are generally taxed only on Australian-sourced income (subject to specific rules).
Establishing tax residency correctly in both countries is critical — and not always straightforward. Double taxation agreements may apply, but they do not automatically eliminate reporting obligations.
Which System Is Better?
There is no universal answer.
Australia’s income tax rates are competitive at middle-income levels, the Medicare levy is modest compared to UK National Insurance, and the absence of inheritance tax is highly attractive for many families. The franking credit system also provides real advantages for investors.
The UK may offer lower capital gains rates in certain scenarios and provides more limited filing obligations for straightforward employees.
The right outcome depends entirely on your income profile, asset base, residency status, and long-term plans.
Need Specialist UK–Australia Tax Advice?
At AUK Tax, we specialise exclusively in UK–Australia cross-border taxation.
Whether you are planning a move, have already relocated, or want clarity on how the two systems interact in your situation, we can help you structure things correctly from the outset.
Get in touch to arrange a no-obligation introductory call. Following that discussion, we will provide a clear and transparent fee proposal tailored to your circumstances.