Although divorce is a commonplace occurrence these days, few people going into their first divorce have much idea about how the process operates. Here is a brief guide. The process for dissolution of a civil partnership is essentially the same, as are the grounds for claiming irretrievable breakdown - with the exception that adultery is not listed as a reason for irretrievable breakdown in civil partnerships.

The basic requirements for obtaining a divorce in England and Wales are that a couple must have been married for a year, the marriage must be legally recognised under UK law and it must have broken down irretrievably. Irretrievable breakdown must be demonstrated to the court by one of five reasons or 'grounds':

• adultery;
• unreasonable behaviour;
• desertion;
• two years' separation with consent; or
• five years' separation without consent.

In practice, if both parties want to be divorced quickly, then the most common ground on which to proceed is unreasonable behaviour. This is used when there has been no adultery and the parties wish to avoid the delay caused by the last three grounds. Unreasonable behaviour can be evidenced by, for example, violence or mental cruelty as well as more subtle complaints such as the exercise of unreasonable control. To support the claim of unreasonable behaviour, one party must agree to give a brief description of the behaviour in the divorce petition.

A 2017 case in the Court of Appeal led to a decison (made 'without enthusiasm') that a wife who wished to divorce her husband, from whom she had been separated for less then two years, could not as the only ground available under which she could obtain a divorce would be if he had shown unreasonable behaviour, which, on the facts, he had not.

It is useful to understand the outline of the process and some of the legal terminology. The party to the marriage who makes the application, or petition, for divorce is known as the petitioner while the other party is called the respondent. The petition for divorce is delivered to, or served on, the respondent. The respondent then has 29 days in which either to admit that the petition is true or to defend the divorce – although defended divorces are very unusual. The respondent agrees by returning an affidavit, a signed statement of the truth, to the court.

Normally, a district judge will then decide on the date of a decree nisi, which is the first step towards the formal divorce. Six weeks after the date set for the decree nisi, the petitioner can apply for the decree absolute. When this is granted, the divorce is final. If the petitioner does not apply for the decree absolute, the respondent may do so three months after that date.

It is beneficial if arrangements concerning any children from the marriage and the split of family assets are agreed without having to go to court. However, it is important to have good legal advice even if these decisions are made amicably. The court will always suggest mediation first in order to reach a mutually acceptable agreement between the parties.

In all, the divorce process is likely to take between five and eight months to complete. It will, however, take longer if there are disagreements over children or money which cannot be settled without the intervention of the court.

In April 2011, a new pre-action protocol was introduced in which the process starts with an attempt to mediate the issues between the divorcing party, the idea being to reduce the cost to them and reduce the necessity to spend time in court.