Strategy for income splitting between spouses

Key takeaways

• The UK taxes spouses individually, not jointly, making it legal and effective to allocate income and assets to the lower-earning partner.
• Transferring income-producing assets to a lower-earning spouse can reduce a household's tax burden significantly.
• Couples can utilise two sets of personal allowances, CGT annual exemptions, dividend allowances, and savings allowances, potentially saving thousands annually.
• Transfers must reflect genuine changes in beneficial ownership, paper-only arrangements risk challenge under HMRC's settlements legislation.

Given the UK’s progressive tax system, married couples and civil partners can reduce their overall household tax burden by arranging their financial affairs to maximise the use of personal allowances, lower income tax bands, and capital gains tax exemptions. One effective strategy to achieve this is income splitting — a tax planning approach that allocates income and gains between spouses to ensure optimal use of lower tax brackets.

This article explores the concept of income splitting, outlines its legal and practical framework, and examines how it can be implemented to take full advantage of the tax allowances available under UK law.

Legal framework: Income splitting within marriage or civil partnership

Unlike many countries, the UK does not have joint taxation for married couples and civil partners. Instead, each individual is taxed separately. However, transfers of assets between spouses and civil partners are generally free from Capital Gains Tax and do not trigger Inheritance Tax, providing a legal and tax-neutral way to redistribute income-generating or appreciating assets.

Crucially, HMRC allows such transfers on a no gain/no loss basis, effectively permitting couples to rearrange ownership of assets to better utilise individual allowances, provided the transfers are genuine and not merely nominal. This remains the case, even for those cases where one of the spouses is non-UK resident.

Optimising use of the Personal Allowance (PA)

As of the 2025/26 tax year, the personal allowance remains at £12,570. If one spouse has income below this threshold, perhaps due to part-time work, childcare responsibilities, or retirement, it may be advantageous to transfer income-producing assets (e.g., shares, rental property interests) to them.

This ensures the income is taxed, if at all, at a lower rate.

For example: John and Alice are married. Alice is employed earning £150,000 a year and has a rental property which generates a profit of £20,000 a year, whilst John stays at home looking after the children with zero earning streams.

In the above, the rental income is being taxed at 45% under Alice, resulting in a tax burden of £9,000 a year. However, if the property was held outright by John, the personal allowance (and the basic rate of tax), will be available - £12,570 being tax-free, and the remainder taxed at 20%, thus reducing the tax liability down to £1,486, a very welcome tax savings of £7,514!

Making use of the Marriage Allowance

For couples where one spouse earns less than the Personal Allowance, and the other is a basic-rate taxpayer, Marriage Allowance allows a transfer of £1,260 of unused allowance to the higher earner, potentially saving up to £252 annually in tax.

Eligibility criteria:

• You must be married or in a civil partnership.
• The lower earner must have income below £12,570.
• The higher earner must be a basic-rate taxpayer (i.e., earning between £12,571 and £50,270).

Income splitting and Capital Gains Tax (CGT)

Each individual is entitled to an annual Capital Gains Tax exemption (Annual Exempt Amount), which is £3,000 per person from April 2025 (down from £6,000 in 2023/24). Couples can, therefore, realise up to £6,000 in gains tax-free if assets are held jointly or appropriately allocated. Furthermore, if one spouses income lies within the basic rate of tax, there is an additional benefit having an initial lower capital gains tax rate (being 18%, up until total income is £50,270, and 24% afterwards).

Continuing with our example above, Alice has been holding shares with an unrealized gain of £10,000 which she now wishes to crystalise. Alice could transfer majority of the assets into John’s name, leaving her only with a £3,000 gain. This ensures the tax-free annual exempt amount for both spouses has been fully utilised (£6,000 tax-free), and benefits from John being a basic rate taxpayer resulting in the outstanding £4,000 being taxed at 18% rather than 24%.

Following the above transfers, the tax due on this disposal is now just £720. In comparison, if the shares were sold under Alice’s 100% ownership, the tax would have been £1,680 (£10,000 minus £3,000 tax-free, taxed at 24%).

Maximising dividend and savings allowances as a couple

Each individual also receives:

• Dividend Allowance: £500 (2025/26), taxed at 0%.
• Savings Allowance: £1,000 for basic-rate taxpayers; £500 for higher-rate taxpayers.
• Savings Nil Rate Allowance: £5,000 tax-free, if this falls within the first £5,000 of taxable income (after non-savings income, such as employment, self-employment, pensions, royalties, etc).

Income splitting through share ownership or joint investment accounts can allow both spouses to benefit from these allowances, rather than concentrating all dividends or savings income in the name of the higher earner.

Practical considerations and anti-avoidance for income splitting

While HMRC permits income splitting between spouses, the “settlements legislation” apply if arrangements are artificial or involve retained control. However, outright gifts between spouses are typically outside these rules - especially where:

• The asset is given unconditionally.
• The recipient gains full control over the income.
• There is no right to claw back the asset or income.

Gifting an income-producing asset (e.g., shares in a family company) without control or on paper only may risk challenge under anti-avoidance provisions. Always ensure the arrangement reflects a real change in beneficial ownership.

Summary: Strategic allocation for efficient household yaxation

Income splitting between spouses is an effective method to reduce the household’s overall tax burden, by carefully reallocating income and assets to make full use of each topic discussed above.

However, such planning should be approached with proper advice, documented transfers, and attention to detail. What may appear as a simple reallocation can become complex, particularly where business interests or trusts are involved.

Speak to our specialists at W1M to review how your assets are currently held and where restructuring could make a meaningful difference for you and your spouse.

FAQs

Is income splitting between spouses legal in the UK?

Yes. HMRC permits income splitting between spouses and civil partners, provided the transfers reflect genuine changes in beneficial ownership and are not merely nominal arrangements to redirect income.

How do married couples split rental income for tax purposes?

For jointly owned rental property, income arising to married couples or civil partners living together is taxed on a 50:50 basis by default, regardless of actual ownership proportions. This can be overridden by submitting a Form 17 declaration to HMRC, but only where the beneficial ownership is genuinely unequal and supported by evidence (e.g. a declaration of trust). The election must be made within 60 days of signing the declaration and cannot be backdated.

Can I transfer shares to my spouse to reduce dividend tax?

Yes, transfers of shares between spouses are generally free from CGT and Stamp Duty. Once transferred, dividend income is taxed on the recipient, meaning both partners can use their individual £500 dividend allowances and, for a lower-earning spouse, the lower dividend tax rates. The transfer must represent a genuine change in beneficial ownership, not just a paper rearrangement.