Marriage (and civil partnership) brings several tax advantages in the UK. Here's everything that changes.
1. Marriage Allowance (£252/year)
If one partner earns under £12,570 and the other is a basic rate taxpayer, you can transfer £1,260 of personal allowance. This saves £252 per year and can be backdated 4 years (up to £1,260 total). Use our marriage allowance calculator to check eligibility.
2. Inheritance Tax — The Big One
Everything you leave to your spouse is completely IHT-free, regardless of amount. Plus, any unused nil rate band transfers to the surviving spouse, potentially doubling their IHT allowance to £650,000 (or £1 million with residence nil rate bands). For a couple with a £800,000 estate, this could save £190,000 in IHT compared to an unmarried couple.
3. Capital Gains Tax
Transfers between spouses are CGT-free. This means you can transfer assets to whichever spouse has the lower marginal rate (or unused annual exemption) before selling. With a £3,000 annual exemption each, a couple can realise £6,000 of gains tax-free versus £3,000 for an individual.
4. Pension Benefits
Most pension schemes provide a spouse's pension if you die — typically 50% of your pension. For defined benefit schemes (like the NHS or teacher's pension), this can be worth hundreds of thousands over a lifetime. Unmarried partners often don't automatically qualify.
5. Council Tax
Married couples sharing a home don't pay more council tax than a single person in the same property. But a single person living alone gets a 25% discount that they'd lose when a partner moves in (married or not).
Total Value of Marriage Tax Benefits
For a typical couple with one higher earner and moderate assets, the marriage tax advantages could be worth £10,000-£200,000+ over a lifetime, primarily from inheritance tax savings. The marriage allowance alone is relatively small, but the IHT benefit is enormous.
Check your marriage allowance eligibility
Marriage allowance calculator →