You must be able to show that your spouse has had sexual intercourse with someone of the opposite sex to use adultery as the grounds for divorce. Proof of adultery can either be an admission of guilt by your spouse or you can provide circumstantial evidence - in either case you will be saying that you now find it intolerable to continue living with your spouse.

You do not need to name the person who committed adultery with your spouse. To do so can complicate proceedings and make the divorce more acrimonious than it need be, particularly if your aim is to secure a quick divorce. If you are intent on naming the other person, referred to as the co-respondent on any court documents, please seek legal advice before doing so.

Adultery is a legal term that relates specifically to heterosexual intercourse. If your partner has been sex with someone of the same sex as your spouse, adultery cannot be cited as a reason for wanting a divorce. In this instance, unreasonable behaviour should be cited.

If the adultery was committed more than six months before you submitted your petition, it will not be accepted as grounds for divorce. The court will assume that you have forgiven your spouse.

You also cannot apply for a divorce on the grounds that you yourself have committed adultery. Your spouse would have to file for a divorce in this instance.

Unreasonable Behaviour

Unreasonable behaviour is something of a catch-all for grounds for divorce and is the most common reason to petition for a divorce.

When citing unreasonable behaviour, the petitioner usually submits a number of examples of such behaviour to demonstrate why he or she can no longer live with their spouse.

Remember, you only need demonstrate behaviour that is unreasonable to you - the court does not insist only consider extreme examples of behaviour to be unreasonable. In fact, your spouse is more likely to agree not to contest a divorce if the unreasonable behaviour does not paint them in too bad a light.

The court will look at your examples of unreasonable behaviour and will grant a divorce if it is assumed that a reasonable person would not be able to live with such behaviour.

Examples of unreasonable behaviour can be very varied - from violence to alcoholism to your spouse being too career-orientated or you sharing no common interests. You should cite three or more examples of unreasonable behaviour and provide examples that show that there is a pattern of such behaviour. The behaviour must also have occurred within the six months preceding the filing of a divorce petition.

Courts do not set a high standard for unreasonable behaviour. The very fact that you are filing for divorce suggests that the behaviour cited is unreasonable to you, but by the same token don't expect minor or trivial examples of behaviour to result in a divorce being granted.

Remember too that details of unreasonable behaviour in an uncontested divorce will not be made public by the court.

Separation

If you are your spouse have not been living together for two years and your spouse does not contest the divorce, a divorce will be granted.

If you and your spouse have not been living together for five years or more, a divorce will be granted even if your spouse contests the divorce petition.

Desertion

Desertion is now the least common reason given in a petition for divorce because it's usually easier to ask for a divorce on other grounds.

Desertion is when your spouse leaves you against your wishes for two years or more. You will need to demonstrate that during that time you wanted your spouse to return and that your spouse abandoned all marital responsibilities during the period of desertion.