This blog post relates to previous divorce laws. On 6 April 2022, the Divorce, Dissolution and Separation Act 2020 was implemented, heralding no-fault divorce. Read more in our blog post: No-fault divorce – the end of the blame game

In order to obtain a divorce, you must prove that your marriage has irretrievably broken down. You must rely on one of five facts, one of which is that the respondent (the person against whom the petition for divorce is issued) has behaved in such a way that the petitioner cannot reasonably be expected to live with them.

At least until very recently this has usually been summarised as unreasonable behaviour. But what exactly is unreasonable behaviour?

What is unreasonable behaviour in divorce?

Unreasonable behaviour remains the most common fact on which to prove the ground for divorce in England and Wales, with 35% of all husbands and 49% of all wives petitioning for divorce citing unreasonable behaviour (reference: 2019 ONS).

The respondent’s conduct (until the case of Owens, often referred to as their unreasonable behaviour) is the behaviour of your spouse that you find unacceptable.

The case of Owens is a reminder to all that the test as to whether the behaviour is unacceptable is not subjective. The question is objective - has the behaviour of your spouse been such that you cannot reasonably be expected to live with them.

What are examples of unreasonable behaviour?

Examples of unreasonable behaviour in divorce could include the following:

• his/her refusal to engage in family life;
• lies and deceit;
• abusive behaviour, physically or mentally;
• spending excessive amounts of money with no good reason, causing financial strain; and
• a relationship with another person (not to be confused with adultery).

The list is not exhaustive by any means.

It is usual practice to include at least 3–5 examples of your spouse’s conduct in the divorce petition. We understand that if you are the party who receives a petition the particulars can be difficult to read.

Importantly, the second element of the test is whether the court is satisfied that, based upon your spouse’s conduct, you can no longer be expected to live with them.

This test has been brought to the forefront by the recent case of Owens. Ordinarily, the second element is not brought in sharp focus because the proceedings progress undefended, but as Mrs Owens learnt to her cost, if defended – which is rare – then it is vital that this second hurdle is also successfully overcome.

Find out more about the divorce process

What is the time frame for using unreasonable behaviour?

If you have not committed adultery or do not wish to wait for two years separation, then your spouse’s conduct is the only fact to rely on to achieve a divorce, allowing you both to move forward with your lives.

The behaviour on which you are relying must have taken place within six months prior to issuing proceedings. For example, if you have lived with your spouse for a year following an episode of domestic violence, then you will not be able to rely on that behaviour alone. However, if the impact of that violence is still affecting you and is still impacting on your relationship, then you may be able to rely on it.

How can I divorce amicably?

Whilst we are without a no fault divorce system, it can be challenging to divorce based upon unreasonable behaviour amicably. However, the particulars could be agreed in advance, for example during mediation, or with the help of solicitors, so both parties decide what is included in the petition. By disputing the particulars (defending the divorce) you could unnecessarily draw out proceedings and incur costs that could be avoided.

Read more: 7 rules for communicating with your spouse during a divorce

Many couples believe that the conduct particulars (as arguably we must now call them) will affect how the financial assets of the marriage will be distributed, or will be seen by others. Neither, in most cases, is the case.

We’re here to help you

We have specialist family lawyers to advise on all aspects of relationship breakdown, including divorce, separation and the resolution of financial and children matters. For more information, please contact our Family Law Team who would be happy to advise you.

Are you considering getting a divorce? Download our free guide and find out the six key decisions you need to make.

[Originally published in September 2018; updated in March 2021]