Adultery and UK law – grounds for divorce and how to apply…

How to use adultery as grounds for divorce in England & Wales

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Originally published on 28th September 2018 at 10:20 AM

What is adultery in English & Welsh law?

Adultery is one of the five 'facts' or 'grounds' that can be used to divorce in England and Wales. According to the Office of National Statistics, 1 out of every 10 divorces that were completed in the UK was granted because of infidelity or adultery.

There are five grounds for divorce in England and Wales. These grounds are listed below:

This blog will cover how you can use adultery as the grounds for divorce in England and Wales.

How to use adultery as grounds for divorce:

What happens in a divorce if you commit adultery under UK law?

If you commit adultery in English law (England and Wales), this can be used as valid grounds for divorce. Divorce law differs in Scotland and Ireland, from that of England and Wales. To find out about the specific divorce law in Ireland and Scotland visit the the Irish or the Scottish government website.

According to English adultery law, if you committed the adultery, you can’t be the one to apply for the divorce. This has to be done by the partner who remained faithful.

Here's a list of essential things you need to know if you are using the grounds of adultery for divorce in English and Welsh law:

  • You must be married for at least a year to get divorced
  • You must start divorce proceedings within six months of finding out that the adultery has taken place
  • Adultery means sex with a member of the opposite sex. Other forms of intimacy outside of sexual intercourse cannot be used in UK (English and Welsh) law
  • The person who was not unfaithful must be the ‘petitioner’ i.e. the person who starts divorce proceedings

How to prove adultery when filing for divorce

The easiest way to divorce using adultery is for the person who has committed the infidelity to admit to it. It can be hard to gather evidence and prove adultery if your ex isn’t prepared to admit it.

You can attempt to prove adultery or infidelity through text messages, hotel room bookings, witnesses etc. However, this route is not advised as it’s likely to lead to further tension between you. If the person who has committed the adultery doesn’t accept that they have been unfaithful, then the other option is to use unreasonable behaviour grounds.

How does adultery affect the divorce paperwork?

The petition:

If adultery is used as the 'fact' or 'grounds' for divorce, then you need to include the date you found out that your ex committed adultery and it must have been less that six months before filing the petition for divorce. If it's been more than six months, you should consider using unreasonable behaviour instead. You could use the adultery as an example of unreasonable behaviour.

The acknowledgement of service:

The acknowledgement of service is a form sent with a copy of the divorce paperwork to the respondent. The questions on this form will change depending on the grounds used. If adultery has been used, then the respondent will have to admit to the adultery on the form.

The decree nisi:

The decree nisi application includes the D84 and D80 form. If you have used adultery, the D84 form is the same, however, the D80 form changes depending on the grounds used, in this case it's the D80 A form.

The decree absolute:

The decree absolute is unaltered by the 'fact' or grounds used in the petition.

I committed adultery - can I file for divorce?

When it comes to divorce law in England and Wales around adultery, you can’t start the divorce proceedings if you are the person who has committed the adultery - it will fall to the other person.

This may not seem fair as it leaves your ex to start the process, especially if they aren't being cooperative. If you feel that your marriage has broken down beyond repair, and your ex won’t start divorce proceedings, then you can use ‘unreasonable behaviour’ as your reason for divorce.

If your ex is being cooperative and they agree to be the petitioner (the person starting the divorce) you can then admit to the adultery on the acknowledgement of service form, and this can be used as proof of the infidelity.

My spouse didn't have extramarital sex, but did get intimate. Is this a valid ground for divorce?

The short answer is no. Extramarital sex can be used as grounds for a divorce (adultery). However, any other forms of intimacy besides sex is not valid when using adultery grounds for divorce in UK law (English and Welsh law). This may seem like quite an archaic law but in this instance, it's easier to use unreasonable behaviour as the reason for ending your marriage. You can use intimacy with another person as an unreasonable behaviour point in the behaviour statement on the petition.

If you’re not sure what grounds to use, book a call to talk to one of amicable’s divorce coaches.

Is It still adultery if you're separated in the UK?

In England and Wales, if you sleep with a new partner after you've separated from your wife or husband (but not yet divorced), then yes. By law, this would still be considered adultery and your ex could use that as a ground for divorce if they wished.

This is because you are still legally married in the eyes of the law. This is even the case if you and your ex have agreed to see new partners. However, this can only be used within six months of your ex finding out about the adultery.

Should I name the other person?

TThere is the option to name the person your ex has had an affair with on the divorce petition. Whilst it’s tempting to do that when the emotions are raw, it doesn't achieve much and gives an additional opportunity for your ex or the person named to object and hold things up. Seek emotional support for help processing the end of the relationship. You can speak to Relate for support or visit the BACP website.

Can you use adultery to dissolve a civil partnership?

No you can’t use adultery as grounds to dissolve a civil partnership, as it must be sexual intercourse with a member of the opposite sex, however you can use your partner’s infidelity as an example of unreasonable behaviour.

If you have any questions, or would like some support, please book a free 15-minute call with one of our experts here.

Hannah Hodgkinson
Hannah Hodgkinson
Hannah Hodgkinson is Head of Marketing at amicable. Hannah has over six years experience working for global NGOs and private consultancies and has a passion for marketing for companies with a social purpose


Great help.

Indispensable service. Can't be more thankful

posted Lloyd Macauley at 10.01.2019 21:33

Can u help me

posted CASSANDRA at 09.02.2019 13:07

Hello Today I received notification by post that I’ve been named as a co-respondent in a divorce case. The petitioner is applying to the courts to claim the costs of the divorce from myself. I don’t deny the affair but as the co-respondent, I wonder if you could provide me advice on the following issues;

Am I legally obliged to sign the Acknowledgement of Service form? What happens if I don’t sign it? Can I be made to pay his court costs?

Your advice would be greatly appreciated

posted Darren Smith at 10.04.2019 15:02