Warnings
An employee issued with a warning after a disciplinary hearing runs the risk of dismissal if they re-offend, particularly while any final written warning is still in force, or “live” (in other words, while the time span of the warning has not yet lapsed).
A live warning can be taken into account in a decision to dismiss or to take other disciplinary action, even if it relates to a different set of circumstances. However, less weight should be given to a warning if the circumstances are unrelated than if it is directly relevant.
The Acas Guidance says that except in agreed special circumstances, warnings or other disciplinary sanctions should be disregarded for disciplinary purposes once a specified period of satisfactory conduct or performance has passed, in other words, once they cease to be “live”. The length of the live period should be agreed when the procedure is drawn up, and set out clearly.
The Acas Guidance (as opposed to the Code itself) suggests up to six months for a first written warning and up to twelve months for a final warning (or “more in exceptional circumstances”).
As a general rule, employers should not take expired warnings into account when deciding to dismiss, but there are exceptions. The Acas Guidance says (page 33): “A decision to dismiss should not be based on an expired warning, but the fact that there is an expired warning may explain why the employer does not substitute a lesser sanction”. In other words, where an employee commits an offence that warrants dismissal, so that the employer has the choice to dismiss or not, the employer can take an expired warning into account in deciding not to be lenient. This was established in the following case:
Mr Webb had been issued with a disciplinary warning for misconduct that expired around three weeks before he was seen with four colleagues watching TV in the locker room during working hours on the night shift. He was dismissed for gross misconduct, but his colleagues all received final warnings. The Court of Appeal said that the dismissal was fair. Dismissal was within the “band of reasonable responses” for all five employees: the employer was free to decide on the lesser sanction of a final warning for the other staff because they had clean disciplinary records, but to decide to dismiss Mr Webb because he did not.
Airbus UK Limited v Webb [2008] IRLR 309 CA