Retirement is the termination of a contract of employment because the employee has reached a certain age.
Because retirement is based on age criteria it conflicts with age discrimination law and can be unlawful under the Equality Act 2010.
Retirement can be a mutually agreed termination where both parties are happy for the employment to end. However in some circumstances the employee may not want to leave employment early and may wish to continue working.
If an employer wants to enforce retirement at a certain age they will need to be able to show that it is for legitimate business reasons that justify the discriminatory effect.
Alternatively employers will need to dismiss employees on grounds of capability or capacity to undertake their work and deal with them in the same way that they deal with all other employees who may not be capable of doing their work.
Retirement can also be related to ill health which raises different legal issues: see Ill health retirement.