A postnuptial agreement can give married couples and civil partners greater financial clarity during the relationship and if they later separate. It is a legal document that records how the couple intend their assets and financial arrangements to be dealt with if they later separate or divorce. It is often used where there are business interests, inherited wealth, property, trusts, pensions or other assets that the couple wants to deal with clearly and carefully.

Postnuptial agreements are not automatically legally binding in England and Wales. However, a properly prepared agreement can carry significant weight if both parties entered into it freely, understood its implications and received appropriate legal advice.

The practical value of a postnuptial agreement therefore depends not only on what it says, but on how it is created, reviewed and used. This guide explains that process from start to finish.

If you are looking for a more general introduction first, read our guide to what a postnuptial agreement is.

How Does the Postnuptial Agreement Process Work?

There is no single standard form for a postnuptial agreement. It should be tailored to the couple's financial circumstances and the issues they want to resolve.

In practice, the process usually involves the following stages.

1. Decide what the agreement needs to cover

The first step is to establish what you want the postnuptial agreement to achieve.

Some agreements address most of a couple's financial arrangements. Others are narrower, perhaps focusing on a new inheritance, a family business or a property that one spouse wants to keep separate.

Depending on your circumstances, the agreement might deal with:

• Property, including the family home and investment property.
• Savings and investments, including particular accounts or portfolios.
• Pensions, and how the parties intend them to be treated.
• Business interests, including shares, companies and family businesses.
• Inheritance and family wealth, including assets already received or expected in future.
• Trust interests, particularly where family wealth is held through trusts.
• Debts and liabilities, including responsibility for particular borrowing.
• Financial provision, including arrangements intended to provide financial security for one spouse.
• Overseas assets, where the couple's finances span more than one jurisdiction.

The aim is to create a clear framework rather than simply list assets. The agreement should explain what the parties intend to happen if the marriage later ends.

2. Provide full financial disclosure

Both parties should provide sufficient financial disclosure before agreeing the terms.

This normally means sharing relevant information about property, savings, investments, pensions, business interests, liabilities and other financial resources.

The amount of disclosure required will depend on the circumstances. Straightforward finances may require a relatively focused exercise, while cases involving substantial assets, companies, trusts or international wealth may need more detailed documentation or valuations.

Disclosure is important because each person needs to understand the financial position before deciding whether the agreement is acceptable. JMW's guidance on contesting nuptial agreements identifies inadequate financial disclosure as one factor that becomes important if an agreement is later challenged.

3. Take independent legal advice

Each spouse or civil partner should have their own solicitor.

Independent legal advice allows each person to understand:

• Their current legal position
• What the proposed agreement means for them
• What rights they may be giving up or limiting
• Whether the proposed terms are appropriate in their circumstances

This is more than a procedural formality. If a postnuptial agreement is later considered by the court, it will be important that both parties understood its implications and entered into it on an informed basis.

4. Draft and negotiate the agreement

Once the finances and objectives are clear, the agreement can be drafted.

The wording may identify which assets are intended to remain separate, how jointly owned assets should be treated, what provision should be made for either spouse and how issues such as business interests or inherited wealth should be approached.

Negotiation may then be needed. This does not necessarily mean the process has become contentious. Both parties are making an agreement that could have important consequences in a future divorce, so each should have the opportunity to obtain advice and propose changes.

5. Sign the agreement

Once the wording has been agreed and each party has received legal advice, the final postnuptial agreement can be signed.

Both people should enter into the agreement voluntarily. Evidence of pressure, coercion or undue influence can affect how much weight a court gives it later.

Unlike a prenuptial agreement, there is no impending wedding date to work around. This usually allows both parties time to consider the financial disclosure, take advice and negotiate the terms carefully.

6. Review the agreement when circumstances change

A postnuptial agreement should not be treated as something that is signed once and then forgotten.

A review clause can provide for the agreement to be reconsidered after a certain period or following major changes such as:

• The birth or adoption of a child
• A substantial inheritance or gift
• The sale or significant growth of a business
• A major change in either person's income
• One spouse reducing or stopping work
• Significant changes to property, investments or pensions
• Changes involving trusts or wider family wealth
• Relocation overseas

A change does not automatically make the existing agreement ineffective. However, it may affect whether its terms remain fair and appropriate.

When Can You Make a Postnuptial Agreement?

A postnuptial agreement can be made at any time after marriage or civil partnership.

Some couples create one soon after marrying because they did not complete a prenuptial agreement beforehand. Others only consider an agreement years later when their financial circumstances change.

A postnuptial agreement can also update or reaffirm an existing prenuptial agreement. For example, the parties may want to revisit earlier arrangements after having children, receiving an inheritance or experiencing substantial business growth.

For more detail on the circumstances that can prompt a couple to make one, read our related guide on why you might consider a postnuptial agreement.

Are Postnuptial Agreements Legally Binding in the UK?

Postnuptial agreements are not automatically legally binding in England and Wales.

The family court retains discretion over financial matters following divorce and cannot be deprived of that power through a private agreement between spouses.

However, a postnuptial agreement can carry substantial weight.

The Supreme Court considered the treatment of nuptial agreements in Radmacher v Granatino. It established that the court should give effect to a nuptial agreement entered into freely by parties with a proper understanding of its implications unless it would be unfair to do so in the circumstances. The judgment considered nuptial agreements generally, including agreements made after marriage.

What makes a postnuptial agreement more likely to carry weight?

The court will consider both the agreement itself and the circumstances surrounding it.

Important factors include:

• The agreement was entered into freely: Neither person should have been subjected to pressure, coercion or undue influence.
• Both parties understood its implications: Each person should know what the agreement could mean for their financial position.
• Both parties received independent legal advice.
• There was appropriate financial disclosure.
• The terms are fair: An agreement that leaves one person unable to meet their reasonable needs may carry less weight.
• The parties' circumstances have not changed so substantially that the agreement has become unfair.
• The needs of any children have been properly considered: Their welfare and reasonable needs cannot simply be overridden by an agreement between their parents.

The court's wider approach to financial provision on divorce is governed by legislation including section 25 of the Matrimonial Causes Act 1973.

What Happens to a Postnuptial Agreement If You Divorce?

If the marriage ends, the postnuptial agreement can provide an important starting point for the financial settlement.

Where both parties accept the agreement and its terms remain appropriate, it may substantially reduce the issues that need to be negotiated. For example, the parties may already have agreed how particular property, business interests or inherited assets should be treated.

The postnuptial agreement is not, however, the same as a final financial order.

Divorce and financial arrangements are separate legal matters. If you reach a financial settlement, it will need to be formalised through a court-approved order.

Where the parties agree the outcome, a solicitor will prepare a financial consent order. If agreement cannot be reached, the court may determine the financial outcome and consider the postnuptial agreement alongside the parties' wider circumstances.

You can find more information on this process from our financial settlement solicitors.

Can a Postnuptial Agreement Be Changed?

Yes. A postnuptial agreement can be revised if both parties agree.

This may be appropriate where the original document no longer reflects the family's circumstances. For example, one spouse may have received a substantial inheritance, a business may have increased significantly in value or the parties may now have children whose needs were not relevant when the original agreement was made.

Significant amendments should be formally documented rather than relying on an informal understanding between the parties.

Both people should take legal advice on the revised agreement, and updated financial disclosure may also be needed.

How Long Does a Postnuptial Agreement Take?

There is no standard timeframe because the amount of work involved varies considerably.

The main factors affecting timing include:

• The complexity of the financial arrangements
• How quickly both parties can provide financial disclosure
• Whether property, companies or other assets need to be valued
• How much negotiation is required
• Whether trusts or overseas assets are involved

Where the parties broadly agree on what they want the postnuptial agreement to achieve and the finances are relatively straightforward, the process is quicker.

More complex financial situations require additional analysis. The priority should be ensuring that each party has enough information and time to make an informed decision, rather than completing the agreement against an artificial deadline.

How Much Does a Postnuptial Agreement Cost in the UK?

There is no single postnuptial agreement cost that applies to every case.

Legal fees will depend on factors such as:

• The number and complexity of assets
• The amount of financial disclosure required
• Business interests or trusts
• Overseas assets
• Any specialist valuation work
• The amount of negotiation needed
• Whether an existing agreement is being amended or a new document is required

Both parties should usually have their own solicitor, so each will incur separate legal fees.

A postnuptial agreement involves an upfront legal cost, but its purpose is to create greater financial clarity. If a divorce later occurs, having a clear framework in place may reduce the number of matters that need to be negotiated, although it cannot guarantee that a dispute or court proceedings will be avoided.

What Are Common Mistakes When Making a Postnuptial Agreement?

The way an agreement is prepared can have a significant impact on how it is treated later.

Common problems include:

• Incomplete financial disclosure: Both parties need sufficient financial information to understand what they are agreeing to. Omitting significant property, businesses, investments or other assets can undermine that process.
• Failing to take independent advice: Each party should have their own solicitor. Independent legal advice ensures that both understand their rights and the effect of the proposed agreement.
• Putting pressure on the other person: A postnuptial agreement should be voluntary. Pressure, coercion or undue influence may affect the weight the court gives it.
• Agreeing unfair terms: Asset protection should not be approached in isolation from fairness. An agreement that makes inadequate provision for one spouse may be vulnerable to challenge.
• Failing to review the agreement: An agreement can become less appropriate as the family's circumstances change. Reviews are particularly important after major financial or family events.
• Ignoring international considerations: If you own overseas assets, have connections with another jurisdiction or expect to live abroad, you will need additional advice. The treatment of nuptial agreements can differ between jurisdictions.
• Assuming the agreement replaces a financial order: A postnuptial agreement sets out the parties' intentions during the marriage. If divorce occurs, the eventual settlement should still be formalised appropriately.

What Are the Limitations of a Postnuptial Agreement?

A postnuptial agreement can provide valuable financial clarity, but it does not remove every area of uncertainty.

Key limitations include:

• It is not automatically legally binding: The family court retains ultimate discretion.
• It cannot guarantee a particular divorce settlement: The circumstances at the time of separation still matter.
• Its terms may need reviewing: Significant changes can affect whether the agreement remains fair.
• It involves legal costs: Both parties should obtain independent advice.
• It cannot conclusively determine arrangements for children: Their welfare must be considered according to the circumstances at the relevant time.
• It cannot remove the legal framework for child maintenance: Parents may make their own arrangements, but statutory child maintenance rules may also apply.

These limitations are also why professional legal advice is important. A well-drafted postnuptial agreement should work within the family law framework rather than attempt to override it.

What Is the Difference Between a Postnuptial, Prenuptial and Cohabitation Agreement?

These agreements have different purposes depending on the couple's relationship status.

• A prenuptial agreement is made before marriage or civil partnership.
• A postnuptial agreement deals with broadly similar financial issues but is created afterwards.
• A cohabitation agreement is different. It is designed for couples who live together but are not married or civil partners, and can record arrangements concerning matters such as property and finances.

The correct document therefore depends on your relationship status, timing and what you want the agreement to achieve.

How Can a Solicitor Help With a Postnuptial Agreement?

Specialist family law advice will ensure the agreement reflects both your financial circumstances and the way the court would approach it in future.

Our family lawyers can help with:

• Identifying the assets and financial matters that should be addressed
• Reviewing and coordinating financial disclosure
• Advising on property, pensions, inheritance and business interests
• Drafting and negotiating the terms of the agreement
• Assessing whether the proposed arrangements are fair and workable
• Reviewing an existing prenuptial or postnuptial agreement
• Coordinating advice involving trusts, substantial family wealth or overseas assets
• Advising where the validity or effect of an agreement is disputed

JMW advises on postnuptial agreements ranging from relatively straightforward arrangements to those involving businesses, property portfolios, trusts and international assets.