The end of a marriage involves enough complexity without also having to decode HMRC guidance. But marriage allowance in the year of separation or divorce is one of the most genuinely confusing areas of UK personal tax — partly because the rules are counterintuitive, and partly because official guidance glosses over the specifics.

This guide sets out exactly what happens to marriage allowance when a couple separates, when they divorce, and what the tax consequences are for the year in which those events occur.

The Fundamental Rule: Marriage Allowance Runs to the End of the Tax Year

When a marriage or civil partnership ends, marriage allowance does not end on the day of the decree absolute or the date you moved out. HMRC’s official position is that marriage allowance granted for a tax year continues until 5 April of that tax year, regardless of what happens in between.

This means: if you separated in November 2025, your marriage allowance continues until 5 April 2026. From 6 April 2026, you are no longer eligible and the allowance stops — but for the year in which the separation occurred, both partners retain the tax treatment they had going in.

In plain terms: separation and even divorce mid-year does not trigger a mid-year reversal of marriage allowance. The benefit and the reduced personal allowance both continue until the tax year ends.

This also means that both the benefit and the burden of the arrangement carry through. If you were the lower earner, your personal allowance remains at £11,310 — not the standard £12,570 — for the full year of separation. If your income rose during that period, you may be paying more tax than you expected. Our article on the hidden tax trap for lower earners explains this risk in detail.

The Separation Year: Full-Year Allowance, New Tax Year Responsibility

For the tax year in which you separate, HMRC treats you as having been married for the full year for the purposes of marriage allowance. This has two implications:

First, the higher earner retains the benefit of the transferred allowance for the whole year and their tax bill is lower than it would otherwise be. Second, the lower earner’s personal allowance remains at £11,310 rather than the standard £12,570 for the whole year — even if they are separated and no longer benefiting from being in the relationship.

Whether this feels fair is a matter of opinion. The practical consequence is that the lower earner pays slightly more tax in the year of separation than they would if the allowance had been cancelled the moment they split up. There is no mechanism to reverse this mid-year.

Divorce Finalised in the Current Tax Year: Same Rule Applies

Even if a divorce is finalised (decree absolute granted) during the tax year, marriage allowance continues until 5 April. This surprises many people who assume that a legal divorce immediately changes their tax status. It does not — not for the purposes of marriage allowance in the year of divorce.

From the following tax year, neither partner can claim marriage allowance based on the dissolved marriage. If either partner remarries, they may become eligible for a new marriage allowance claim based on the new marriage.

What Both Partners Need to Do After the Tax Year Ends

The Lower Earner (Who Transferred the Allowance)

After the final tax year of the marriage, the lower earner’s personal allowance automatically reverts to the standard amount (£12,570 for 2025/26) for the following year. You should check your new tax code at the start of April to confirm it shows 1257L rather than the N-suffix code associated with marriage allowance. Our marriage allowance tax code guide explains exactly what those letters and numbers mean and what a correctly updated code should look like.

The Higher Earner (Who Received the Transferred Allowance)

Similarly, HMRC should update the higher earner’s code automatically to remove the M-suffix from the following April. But you should verify this. If the M-suffix persists after separation or divorce, contact HMRC immediately — you are receiving a tax benefit that you no longer qualify for, and HMRC will eventually reclaim it. Our guide on when you must cancel marriage allowance covers the exact cancellation process and what HMRC does if incorrect claims are not corrected promptly.

How to Notify HMRC of Separation or Divorce

HMRC does not receive automatic notification of separations or divorces. You must tell them. There are three ways:

• Online: Log into your Personal Tax Account and update your marital status
• Phone: Call 0300 200 3300 and ask to update your personal details and cancel marriage allowance from the new tax year
• Self Assessment: If you file a Self Assessment return, update your marital status on the return

You should notify HMRC even if the tax year has not yet ended — they will note the change and action it from the following April.

What If You Reconcile During the Tax Year?

If you and your partner separate and then reconcile within the same tax year, marriage allowance continues as it was — because from HMRC’s perspective, you remained married throughout. There is nothing to report to HMRC in this case, assuming the allowance was never cancelled.

If you had already cancelled the allowance during the separation and then reconciled, you would need to reapply if you wished to reinstate it. You cannot backdate the cancellation period.

Informal Separation vs Legal Separation: Does the Distinction Matter?

For marriage allowance purposes, HMRC does not draw a sharp legal line between informal and legal separation. What matters is whether the couple is living together and treating themselves as a married couple for tax purposes. In practice:

• Couples living apart temporarily (e.g. due to work) but not separated in a relationship sense: marriage allowance continues normally
• Couples who have separated permanently but not yet divorced: you should cancel marriage allowance from the following tax year, even without a formal legal decree
• Couples who have divorced legally: you must cancel from the new tax year following the divorce

⚠️ Do not assume that just because you are separated but not yet divorced that HMRC automatically knows or cares. It does not. Cancellation is always your responsibility to initiate.

Overpayments and Underpayments in the Year of Separation

Can the Higher Earner Get a Refund for the Year of Separation?

No. Marriage allowance for the year of separation is treated as legitimately claimed, even after the couple splits up. Neither partner can claim a refund of the allowance for the period of the tax year after separation occurred. The full-year treatment is final.

Can the Lower Earner Recover Their Lost Personal Allowance for That Year?

No. The same rule applies in reverse. The lower earner cannot recover the £1,260 of personal allowance they transferred, for the year of separation. It is treated as having been validly transferred for the entire year.

Remarriage and Marriage Allowance: Starting Fresh

If either partner remarries — whether in the same tax year as the divorce or a later one — a new marriage allowance claim can be made for the new marriage, provided both partners meet the standard eligibility criteria.

There is no penalty or waiting period related to the previous marriage. Marriage allowance is assessed on a tax-year basis and each marriage is treated independently. Before reapplying, it is worth reviewing the eligibility conditions carefully — in particular the higher-rate threshold rules and whether either partner has investment income that affects their adjusted net income.

Note: If you remarry within the same tax year you divorced, HMRC may require you to confirm which marriage the allowance relates to. This is rare but can cause administrative delays. Apply as soon as the new marriage is registered.

What About the £1,008 Backdated Refund — Does Divorce Affect It?

If you were eligible for marriage allowance in earlier years and never claimed it, you can still backdate the claim for up to four years — including years when you were married and now divorced. Divorce does not eliminate the right to claim for past eligible years.

The application for backdated years must cover only the tax years during which you were actually married. If you were married from 2019 to 2025, you can claim for 2021/22, 2022/23, 2023/24, and 2024/25 if you were eligible in those years.

What About Death — Rather Than Divorce?

If your marriage ended because your spouse passed away rather than through separation or divorce, the rules are slightly different. The allowance still continues to the end of the tax year, but there are additional opportunities around backdating and estate claims that do not apply in a divorce situation. Our full guide on marriage allowance after death of a spouse covers everything you need to know in that scenario.

Frequently Asked Questions

Does my marriage allowance change the month I separate? No. Marriage allowance does not change mid-year regardless of when separation occurs. Both partners retain their current tax treatment until 5 April.

My divorce was finalised on 10 March 2026. When does marriage allowance stop? From 6 April 2026 — the start of the following tax year. For 2025/26, the allowance continues in full even though the divorce was finalised in March.

I forgot to cancel marriage allowance after my divorce last year. What do I do? Contact HMRC as soon as possible. Explain the oversight and ask them to cancel from the current tax year. See our cancellation guide for the process and what penalties to expect (hint: voluntary disclosure is always treated more favourably).

Can my ex-partner cancel the marriage allowance without my consent? Yes. Either partner can contact HMRC to cancel the arrangement. You do not need both partners to agree. If your ex-partner cancels the allowance, HMRC will inform you via updated tax codes.

Final Thoughts

Marriage allowance in the year of separation or divorce follows a clear rule that few people know: it runs to the end of the tax year regardless of when the split happens. The financial implications are modest in most cases, but misunderstanding the rules can create incorrect tax codes that persist for years.

The most important action is simple: notify HMRC at or near the start of the new tax year following your separation or divorce. It takes one call or five minutes online, and it prevents the kind of administrative problem that is always more stressful to unwind than it was to prevent.

For the other major life events that affect marriage allowance, see our guides on death of a spouse, when to cancel, and the tax code changes you should expect.