Void & voidable marriages — what are they & when can you annul?

Originally published on 26 August 2022 and updated on 4 December 2025.

A void marriage is one that’s invalid from the outset because it’s considered to be unlawful. However, a voidable marriage is one that’s flawed in its validity but continues to exist until a Nullity of Marriage Order is pronounced.

Following the breakdown of a marriage or civil partnership, the vast majority of couples will have a divorce or dissolution (for civil partnerships). However, for some couples an annulment may be more appropriate. 

Here, specialist family lawyer Amy Harris from our Brabners Personal team explains how and when a marriage can be annulled as well as how to know if a marriage is void or voidable.

How to annul a marriage

The process for legally terminating a marriage that’s void or voidable is known as annulment (sometimes known as ‘nullity’). These proceedings are rare but may be appropriate where parties have cultural or religious reasons for opposing divorce or dissolution.

To start nullity proceedings, you’ll need to show that the marriage:

1. was never legally valid (‘void’)
2. was legally valid but meets at least one of the conditions that make it ‘voidable’.

When can I annul a marriage?

You can apply for annulment in the first year of your marriage or at any time after. However, if you apply years after the wedding, you might be asked to explain the delay to the court.

What are the grounds for annulment?

Sections 11 and 12 of the Matrimonial Causes Act 1973 set out the grounds with which you can apply for an annulment if you can prove that your marriage is void or voidable.

How to know that a marriage is void

There are four grounds where a marriage is ‘void’:

1. You’re already married or have entered into a civil partnership.
2. You’re closely related and prohibited from marrying each other.
3. Either one of you was under 16 at the time of the marriage.
4. The marriage was a polygamous one that was entered into outside of England and Wales, while at least one of you was living in England and Wales. Please note that there are some circumstances where a polygamous marriage will be valid, so it’s always best to take specialist advice.

When the courts rule that a marriage is indeed void, it’s treated as though it never happened. However, you must still apply for a Nullity of Marriage Order, which will allow you to remarry in the future.

How to know that a marriage is voidable

There are seven grounds where a marriage is ‘voidable’:

1. The marriage wasn’t consummated, owing to the wilful refusal of the respondent to consummate it.
2. You were pressurised into getting married.
3. One of you was suffering from a mental health issue at the time of marriage. This would need to be a serious medical disorder within the meaning of the Mental Health Act 1983.
4. Your spouse had a sexually transmitted disease when you got married and you didn’t know about it.
5. Your wife was pregnant by another man when you got married.
6. One of you had undergone gender recognition before marriage and hadn’t told the other.
7. An interim gender recognition certificate was issued to a party after the marriage.

Unlike void marriages, a voidable marriage will be seen by the law as having been valid up until the date of annulment.

Can I annul a civil partnership?

A civil partnership must meet two specific criteria for it to be considered legal:

1. Both parties must be over the age of 16.
2. Both parties mustn’t be married or in a civil partnership with someone else.

If the civil partnership doesn’t meet these criteria, you can apply to the court to have the partnership annulled.

How to apply for an annulment

1. Fill in a nullity application form and send two copies to the court (always keep your own copy). The cost of the application is £593. Once you’ve submitted your nullity application, the court will send you notice that your application has been issued.
2. The other spouse or civil partner must then respond to your application within 14 days, stating whether or not they agree with the marriage being annulled.
3. Once they’ve responded, you’re then able to apply for a conditional order (previously known as a ‘decree nisi’) which will confirm that the court accepts the marriage is applicable to be annulled. You must then fill in an application for a conditional order to receive such an order.
4. Following this, you must wait six weeks after the conditional order before you can apply for a final order (previously called a ‘decree absolute’). This final order is the legal document which states the marriage has been formally annulled. You must fill in the final order application form in order to receive such an order.
5. Once the application has been submitted to court, it’ll check whether there are any reasons why the marriage can’t be annulled. If there are none, the court will issue a ‘decree of nullity’ or ‘nullity of marriage order’. This confirms that you’re no longer married. If your marriage was void, the decree or order will confirm that you were never legally married.
6. There may also be financial matters to address as part of the annulment. If a marriage is void or voidable (subject to the circumstances of the case), financial claims may also be available in the same way as they are for a divorce. 

Talk to us

If you’re thinking about seeking an annulment of a marriage or civil partnership, it’s critical to take trusted legal advice to ensure that you understand your position and the available options, as well as anticipate any financial claims that could follow. 

Our award-winning family law team is recognised by The Times Best Law Firms as among the best in the country. Speak to our specialist divorce and financial settlement solicitors today by calling 0333 004 4488, emailing family@brabners.com or completing our contact form below.

If you’re looking for the very best in personal legal advice, discover Brabners Personal — our solution that provides you with easy access to a wealth of trusted experts who can help you to plan and protect your future.