Civil Partnership vs Marriage: Are There Any Tax Differences in 2026/27?
Civil partners and married couples get identical tax treatment in the UK in 2026/27 — the same Marriage Allowance, Capital Gains Tax transfers and Inheritance Tax exemption. Here is what is, and is not, different.
The short answer: none
Since civil partnership was introduced in the UK (2005 for same-sex couples, extended to opposite-sex couples from December 2019), HMRC has treated civil partners identically to married couples for every area of tax. This article runs through exactly what that means in practice for 2026/27, because the assumption that civil partnership might be a "lesser" or differently-taxed status is common but incorrect.
Marriage Allowance Calculator
Calculate the £252/year saving from transferring £1,260 of unused Personal Allowance to your spouse. Plus backdating up to 4 years.
Open Marriage Allowance calculatorMarriage Allowance applies to civil partners too
Despite its name, the Marriage Allowance — letting one partner transfer £1,260 of unused Personal Allowance to the other, worth up to £252 a year in 2026/27 — is available to civil partners on exactly the same eligibility terms as married couples: one partner earning below the Personal Allowance and the other a basic-rate taxpayer.
Capital Gains Tax: identical no gain/no loss treatment
Civil partners living together can transfer assets between themselves at any time without triggering Capital Gains Tax, using the same "no gain, no loss" rule that applies to married couples. If a civil partnership dissolves, the same rules that apply to divorcing spouses apply equally: transfers remain no gain/no loss for up to three tax years after the couple stop living together, or indefinitely if made under a formal dissolution agreement or court order.
Inheritance Tax: the same unlimited exemption
Gifts and inheritances between civil partners — whether during life or on death — are completely exempt from Inheritance Tax, exactly as they are between married couples, with no upper limit. The Residence Nil-Rate Band and standard nil-rate band transfer between civil partners on death using the same rules that apply to spouses.
uk-marriage-allowance-complete-guide-2026Who can now form a civil partnership
Civil partnership was originally introduced in 2005 specifically for same-sex couples, at a time when marriage was not yet open to them. Since the Civil Partnership (Opposite-sex Couples) Regulations 2019 came into force in December 2019, opposite-sex couples in England, Wales and Scotland (with Northern Ireland following) have also been able to form civil partnerships — meaning any couple now has a genuine choice between marriage and civil partnership, with no tax consequence either way.
Bottom line
There is genuinely no tax reason to prefer marriage over civil partnership, or vice versa — HMRC treats both identically across Income Tax, the Marriage Allowance, Capital Gains Tax and Inheritance Tax. The choice between the two comes down entirely to personal preference, not tax planning.
Sources
- GOV.UK: Marriage Allowance
- GOV.UK: Register a civil partnership
Frequently asked questions
Is there any difference in tax treatment between marriage and civil partnership?
No. For Income Tax, Capital Gains Tax, Inheritance Tax and all other UK tax purposes, civil partners are treated identically to married couples. The Marriage Allowance, the spousal Inheritance Tax exemption, and the no gain/no loss Capital Gains Tax transfer rules all apply equally to civil partnerships.
Can civil partners claim the Marriage Allowance?
Yes. Despite the name, the Marriage Allowance is available to registered civil partners on exactly the same terms as married couples — up to £252 a year in 2026/27 by transferring £1,260 of unused Personal Allowance.
Who can enter a civil partnership in the UK?
Since December 2019, civil partnership has been open to both same-sex and opposite-sex couples in England, Wales and Scotland (and later Northern Ireland), giving couples a genuine choice between marriage and civil partnership with identical legal and tax consequences.
Does dissolving a civil partnership work the same as divorce for tax purposes?
Yes. The dissolution of a civil partnership is treated the same as a divorce for tax purposes, including the Capital Gains Tax no gain/no loss window on separation (up to 3 tax years, or unlimited under a formal agreement) and Inheritance Tax rules on gifts between former partners.
Why might a couple choose civil partnership over marriage?
Reasons are entirely personal rather than tax-driven — some couples prefer the legal and historical distinctiveness of civil partnership, or have personal, cultural or religious reasons for avoiding the institution of 'marriage' specifically, while still wanting the same legal recognition and protections.
Do civil partners need to do anything differently when filing a tax return?
No — HMRC forms and Self Assessment treat 'spouse' and 'civil partner' identically throughout, and civil partners tick the same boxes and follow the same processes as married couples.
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Related reading
Cohabiting Couples and Tax: The Legal Differences From Marriage in 2026/27
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Marriage and Civil Partnership Tax Benefits in the UK 2026/27 — A Complete Overview
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