Article reference: UK-IA-FAM16

Divorce: unreasonable behaviour

This article talks about what constitutes unreasonable behavior during a divorce. It gives you information about the law as well as examples of how it applies.


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What behaviour is "unreasonable" and why does it matter

How can i tell whether behaviour is 'unreasonable'?



What behaviour is “unreasonable” and why does it matter?

It matters primarily because the law says it matters. As by now you will be aware the law offers several grounds for divorce. If you want a divorce you have to “qualify” by meeting one of the statutory grounds.

In passing there is a secondary reason. The law is clear that who wins what in a divorce cannot and will not affect the subsequent financial and children proceedings. However, that is not how it works in practice. Every judge is a human being. He or she is no less subject to sub-conscious influences than the rest of us. If you have agreed in your divorce negotiations that your behaviour has been unreasonable then your ex-spouse’s solicitor will be very quick to use the circumstances against you when it comes to sorting out financial matters or children arrangements.

The problem is that if you do not defend against allegations appearing in the final version of the divorce petition, whatever you have “agreed” becomes uncontested truth. If you agree that you have frequently raised your voice, it will follow that you are subject to bouts of violent temper. If you rush out of the house to avoid a shouting match, you will be cast as a loner with insufficient social skills to bring up children. Yoiu cannot win. (But in a moment we will tell you how you can).

It is not just about what is in the petition you have agreed not to defend. It is also about how you behave in court. No judge will ever admit to being prejudiced by someone’s clothes or hair or loud voice or obvious poverty, But they all are. Remember again, these are human beings, making decisions in your particular case. They can decide pretty much what they like. Inevitably, they do not always get it right. A physically attractive person with a pleasant manner will be favoured. Reason will be favoured over anxiety or anger. Where young children are concerned, women will be favoured over men. It may even be assumed that a man can more easily maintain an income (children apart).

The only way to avoid this unidentifiable prejudice is for you to be the petitioner and persuade your ex-to-be to take the flak. This is a horrible situation, but you should face it. It is so easy to go for a very simple divorce, only to find you are spending another three years fighting over money or children, or both. Back now to what may be “unreasonable”.

'Unreasonable' behaviour petitions tend to result in far more legal battles than petitions based on any of the other four grounds. Nobody likes to be accused of behaving so badly that their partner “cannot reasonably' be expected to live” with them. People may well feel that their partner has behaved just as badly or even worse. This can result in both sides feeling very angry with each other which can make reaching an agreement difficult, if not impossible.


R. is having a sexual relationship with CR and wants to divorce P. for 'unreasonable' behaviour. In this case it might be better for P. to divorce R. for adultery.

P. and R. want a divorce. P. feels that R. has behaved 'unreasonably'. R. is having a sexual relationship with someone else. In this case P. could divorce R. for adultery rather than 'unreasonable' behaviour.

If this is not possible, great care should be taken when drafting the petition. The allegations of unreasonableness must be strong enough to stand up in court but should cause as little offence as possible to the other side. Sometimes this can be done by agreeing the incidents of 'behaviour' to be included in the petition. Other  careful wording can also 'soften the blow'.

How can I tell whether behaviour is 'unreasonable'?

There is not easy answer to this. Some cases are very straightforward, like violence, for example. In many cases it's a question of the particular effect the behaviour of one partner has on the other. If the effect is mild (irritation, annoyance, boredom etc.) it is not sufficient. If the effect is more dramatic and this is clear to your partner, it may well be sufficient. The question the judge asks her/himself is: 'Would a reasonable person conclude that this person cannot be expected to live with his/her partner?'

Example 1: R. tends to squeeze toothpaste in the middle. P. is a very orderly person and this annoys him/her.

A reasonable person would probably conclude that this was part of the wear and tear of living with someone and that it was not unreasonable to expect P. to put up with it.

Example 2: P. has a traumatic childhood experience involving a motor accident in which she was injured.

R knows all about this and how it has affected P. R deliberately drives dangerously in order to upset R.

Here a reasonable person might conclude that it is unreasonable to expect P. to continue living with R. because R.'s behaviour has a very strong effect on P., R. knows the effect it has and R. could fairly easily change his behaviour but deliberately chooses not to.

In general a number of different types and incidents of unreasonable behaviour are set out in petitions. It is important that at least one of these has taken place within six months before starting divorce proceeding, otherwise, as in adultery, you're presumed to have forgiven your partner.

Finding the Documents

Net Lawman sells all the forms, documents and draft letters you will need for a simple undefended divorce. You will find them at Divorce Forms and Documents.

Please note that the information provided on this page:

  • Does not provide a complete or authoritative statement of the law;
  • Does not constitute legal advice by Net Lawman;
  • Does not create a contractual relationship;
  • Does not form part of any other advice, whether paid or free.
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