When dismissing someone, you must comply with their employment contract and your policies and procedures - in particular the company's disciplinary procedure. If these are below minimum legal standards, apply the legal minimum instead.
Remember to follow any data protection policies and notices you have. You should tell employees the types of data you might collect about them and what you do with it in a Data Protection Privacy Notice/'Fair Processing Statement' - a statement describing how you collect, use, retain and disclose personal information. For further information read Data protection and employees.
Advance notice of termination is required, as specified in the contract of employment, but cannot be less than one week for each year of service, with a minimum of one week and a maximum of 12 weeks. This is known as the statutory minimum notice period.
Don’t do or say anything that might destroy or seriously damage your relationship of trust and confidence with an employee, without justification. Otherwise they may resign and consider themselves constructively dismissed and claim wrongful dismissal or unfair dismissal.