In some industries, employers provide accommodation to employees because this is required by the nature of the job. There are no tax charges in respect of the provision of living accommodation where

• it is necessary for the proper performance of the employee’s duties that he or she should reside in the accommodation, or
• the accommodation is provided for the better performance of the employee’s duties, and the employment is one of the kinds for which it is customary for employers to provide accommodation for the employee, or
• there is a special threat to the employee’s security, special security arrangements are in force and the employee resides in the accommodation as part of those arrangements.

However, there can be other scenarios whereby an employee is provided with living accommodation and is allowed to sub-let the property. If this is the case, and even if the employee does not sub-let, the ability to sub-let is regarded as money's worth to the employee and will give rise to an earnings charge. 

This issue is covered in HMRC’s manuals. HMRC makes the point that the ability to sub-let is unlikely to be encountered that often in practice.