It is not only assets that come into a marriage – debts do too. Student loans, credit-card balances, car finance, business borrowing or a partner's existing liabilities can all raise the same worry: if we divorce, who is responsible? The reassuring general rule in England & Wales is that a debt in one partner's sole name stays their responsibility – marriage does not make you liable for your partner's borrowing. But debts and assets are weighed together on divorce, so it is not quite that simple. A prenup can record which debts each partner brought in and confirm they remain that person's responsibility. This guide explains how debts are treated, what a prenup can and cannot do, and the important difference between sole and joint debt.
How debts are treated on divorce
Generally, a debt in one partner's sole name remains their responsibility. Marriage does not automatically transfer or share one person's borrowing. However, on divorce the court looks at debts and assets together as part of the overall financial picture – so one partner's debts can still affect the settlement indirectly. For example, if one partner is weighed down by pre-marital debt, the split of the remaining assets may be adjusted to reach a fair outcome. See how debt is split in a divorce and how assets are divided.
Sole debt vs joint debt
The distinction that matters most is between debt in one name and debt in both:
| Type of debt | Who is liable to the lender | Prenup effect |
|---|---|---|
| Sole debt (one partner's name) | That partner alone | Can confirm it stays theirs |
| Joint debt / guarantee | Both partners, to the lender | Cannot override the lender's rights |
| Debt taken on together in marriage | Depends on the borrowing | Usually treated as shared |
The key limit: a prenup governs the position between the two of you, but it cannot change what a lender is entitled to pursue under a joint loan or guarantee. If your name is on the agreement with the bank, the bank can still come to you regardless of what your prenup says between the couple.
What a prenup can do
A prenup can record which debts each partner brought into the marriage and confirm that they remain that partner's responsibility. Listing debts honestly in your financial disclosure is part of this – and it protects both of you from nasty surprises. Full disclosure of liabilities is just as important as disclosure of assets; concealing a large debt can undermine an agreement in the same way as hiding assets. If you are entering marriage carrying significant borrowing, see prenups when you have significant debt.
A note on joint and new debt
Debts taken on together during the marriage – a joint mortgage, a shared loan – are usually a shared matter, and a prenup will not push them onto one partner in a way the court sees as unfair. As always, the court keeps discretion to reach a fair outcome (see are prenups legally binding?). Still, clarity about pre-existing debt is a sensible and common reason to make a prenup, especially where one partner is bringing in far more borrowing than the other.
Debt and prenups: keeping liabilities where they belong
On debt and prenups, the aim is to keep pre-marriage liabilities with the partner who incurred them. A prenup can record each partner's debts at the date of marriage and confirm they remain that person's responsibility. It cannot change what a lender can pursue under a joint loan, and the court keeps discretion over the overall settlement – but clarity about pre-existing debt protects the debt-free partner and prevents nasty surprises.
Why the prenup carries weight: Radmacher
A prenup recording who owns which debts has force because of Radmacher v Granatino (2010), in which the Supreme Court held that a court should give effect to a freely made, fair agreement unless it would be unfair to hold the parties to it. It is not automatically binding as between you – the court keeps its discretion under the Matrimonial Causes Act 1973, and needs come first – and, crucially, it can never change what a lender is entitled to pursue. But a fair agreement, made with full disclosure of liabilities and independent legal advice on both sides, gives a court a clear steer on how pre-marital debt should be treated in the settlement between the two of you.
A worked example: student debt and a business loan
Imagine one partner enters the marriage with £45,000 of student loans and a £30,000 loan taken out to start their business, both in their sole name. The other partner has no debt. A prenup can record these liabilities and confirm they remain the borrowing partner’s responsibility, so that on divorce the debt-free partner is not, in effect, made to pay down borrowing they never benefited from. If the couple later take out a joint mortgage, that is shared – and the prenup will not, and should not, try to push it onto one of them alone. The agreement draws a clear line between what each brought in and what they took on together.
Protecting yourself where a partner has significant debt
If you are marrying someone carrying substantial borrowing, a few practical steps help alongside the prenup:
- Keep finances separate where you can, so a partner’s sole debt is not paid from joint funds (see joint vs separate accounts).
- Think hard before co-signing or guaranteeing a loan – that makes you liable to the lender regardless of any prenup.
- Disclose everything honestly, because concealing a debt can undermine the agreement just as hiding assets does.
- Revisit the position if borrowing changes materially, using a review clause.
For the wider picture where debt is significant, see prenups when you have significant debt.
Business debt and guarantees: a special case
Business borrowing deserves particular thought, because it often comes with personal guarantees. If one partner has guaranteed a company loan, they are personally on the hook to the lender if the business cannot pay – and, as with any joint or guaranteed debt, a prenup cannot change what the lender is entitled to pursue. What a prenup can do is record, between the couple, that the business and its associated borrowing are one partner’s separate responsibility, so the other is not expected to shoulder a liability from a venture they had no part in. This matters most where a self-employed partner or a business owner carries significant borrowing. Disclose these liabilities honestly – a large undisclosed guarantee can undermine an agreement just as a hidden asset would.
A short checklist for debts in a prenup
- List every debt each partner brings in – loans, cards, car finance, student loans, business borrowing – with balances.
- Identify sole versus joint liabilities, since only sole debts can cleanly be assigned between you.
- State whose responsibility each is as between the couple.
- Be cautious about co-signing or guaranteeing, which makes you liable to the lender directly.
- Disclose fully, because concealing debt weakens the agreement.
Handled this way, a prenup keeps pre-marriage liabilities with the partner who incurred them and protects the debt-free partner from unpleasant surprises. For the wider approach where debt is significant, see prenups when you have significant debt.
Where pre-marriage debt sits in the statute, and what a court can do with it
The statute deals with debt under the heading of obligations. Section 25 of the Matrimonial Causes Act 1973 requires the court to consider the financial needs, obligations and responsibilities which each party has or is likely to have in the foreseeable future, so a student loan, a business overdraft or a credit card balance brought into the marriage is on the court's list from the start. The court works from net figures, deducting liabilities from assets before it divides anything, which is why one partner's debt affects the other even though the lender can only pursue the borrower. Under the same section the court may also take conduct into account where it would be inequitable to disregard it, and money one spouse recklessly ran through before or during the marriage can in a clear case be added back as if they still had it.
What a court can do about debt is limited to the two of you. A consent order under section 33A of the Matrimonial Causes Act 1973 can allocate liabilities between you and require one spouse to indemnify the other, and section 24 can transfer a house together with its mortgage. None of that binds the lender. A joint loan or a guarantee remains enforceable against both names until it is repaid or the lender agrees to release one of you, and a court order saying otherwise gives the released spouse a claim against the other, not against the bank.
A prenup works inside those limits and does the one thing the court cannot do afterwards: it records the position at the start. List each debt in the financial disclosure with its balance, lender, date and purpose, because the Law Commission's recommended standard is disclosure of material information and a partner's liabilities are as material as their assets. State that pre-marriage debts remain the borrower's responsibility and that debts taken on together for the family are shared. Under Radmacher v Granatino a court will give effect to an agreement freely entered into with a full appreciation of its implications unless it would be unfair, and a clear allocation of who owed what on the wedding day is rarely unfair to anyone.
Marrying with significant debt
The same rules apply when the debt is large enough to worry about. A student loan, business borrowing or a credit card balance in one partner's sole name stays that partner's legal responsibility; marriage does not make the other spouse liable for it. What changes is the overall picture on divorce, because the court weighs both partners' obligations before deciding what is fair, so significant debt on one side reduces what there is to share and can affect the other partner's outcome. A prenup cannot stop a lender pursuing a joint loan, but it can record each partner's debts at the date of marriage, confirm they remain that person's responsibility, and protect the debt-free partner from carrying borrowing they never took on.
Debt and prenups: FAQs
Does a debt clause carry weight after Radmacher?
Between the couple, yes – since Radmacher v Granatino (2010) a fair, well-disclosed agreement is given real weight, but it cannot bind a lender (see are prenups legally binding?).
Should I avoid co-signing my partner’s loan?
Be cautious – co-signing or guaranteeing makes you liable to the lender directly, whatever your prenup says between the two of you.
Am I liable for my partner's pre-marriage debts?
Generally not for debts in their sole name, but they affect the overall settlement (see how debt is split in a divorce).
Can a prenup protect me from my partner's debts?
It can confirm whose debt is whose (see prenups when you have significant debt).
Does a prenup override a joint loan?
No – a lender can still pursue anyone named on a joint loan or guarantee, whatever the prenup says between the couple.
Should I disclose my debts in a prenup?
Yes – full disclosure of liabilities is as important as disclosing assets (see full and frank disclosure).
What happens to debts we take on during the marriage?
Those are usually treated as shared; a prenup mainly addresses pre-existing debt (see what to include in a prenup).
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UK Prenup is not a law firm and does not provide legal advice. A prenuptial agreement in England & Wales is not automatically binding, and both partners should take independent legal advice before signing.