Unfair dismissal is the term used in English, Welsh and Scottish Law to describe an employer's action when terminating an employee's employment contrary to the requirements of the Employment Rights Act 1996. The concept of Unfair Dismissal therefore has a narrower meaning than is commonly understood. In particular, a termination by the employer in breach of the employee's contract of employment (in other words a dismissal without notice, where the employer is obliged to give notice) is described as "wrongful dismissal", and not as unfair dismissal.

Where an employee has grounds to believe that he or she has been discriminated against in being dismissed, other laws may be relevant, such as (in Britain) the Race Relations Act, the Disability Discrimination Act 1995 and the Sex Discrimination Act 1976.

Where the employee resigns or terminates his contract (without notice) due to some action on the part of the employer which would entitle the employee to terminate without notice (whether or not the employee actually gives notice), this is known as constructive dismissal. The normal circumstances in which an employee would be so entitled are in cases of a "fundamental breach of contract" (also known as a "repudiatory breach of contract") by the employer.

Claims of unfair dismissal can only be brought before an 'employment tribunal'. There are strict and very short time limits for claims of unfair dismissal. Normally a claim must be brought within three months of the last day of employment, counting the last day of employment as the first day of the three month period. This rule is often summarised as "three months less a day".

The claim must be lodged using the prescribed form ET1 which can be obtained from the Employment Tribunals Service.

Employees may bring such claims themselves, either with or without representation. Solicitors and certain other representatives regulated by the Ministry of Justice may represent employees in Employment Tribunal proceedings. Trade unions may support employees' claims, and independent arbitration and conciliation services may be called upon.

There are a number of reasons for dismissal which are automatically unfair and apply to all employees regardless of length of service, such as pregnancy, or having previously asserted certain specified employment rights. For those employees who have a year's continuity of service at the date of dismissal, or who have been dismissed without notice and are within a week of gaining a year's continuity of service, they may only be dismissed if

• the employer dismisses for a potentially fair reason,
• the employer follows a fair procedure, and
• the employer acted reasonably in treating that reason as sufficient for dismissal.

There are now six potentially fair reasons for dismissal:

• a reason related to the employee's conduct
• a reason related to the employee's capability or qualifications for the job
• because the employee was redundant
• the employee had reached normal retirement age in accordance with the Employment Equality (Age) Regulations 2006
• because a statutory duty or restriction prohibited the employment being continued
• some other substantial reason of a kind which justifies the dismissal.