In most circumstances, you have got one year to assess employees (make sure you have a probationary period), and during that time you can dismiss them without any fear of being taken to an employment tribunal and accused of unfair dismissal. However, you will automatically be guilty of unfair dismissal, regardless of the length of time the employee has worked for you, if the reasons for sacking them are any of the following:

• Trade union membership or activity
• Not being a member of a trade union
• Acting as a representative for negotiations about redundancy
• Being pregnant or taking maternity leave
• Taking action on healthy and safety grounds
• Trying to enforce statutory employment rights (such as requesting a written statement or refusing to allow an employee to bring a work colleague or trade union representative to any disciplinary grievance hearing)
• Refusing to do shop or betting work on a Sunday
• Acting in his or her role as a pension scheme trustee
• Reasons relating to the national minimum wage
• Reasons relating to the working time regulations
• Reasons relating to the transfer of employment rights from one employer to another
• ‘Whistle blowing’, where protection is given by the Public Interest Disclosure Act 1998

And if you dismiss an employee who would qualify for paid suspension on medical grounds, you could be guilty of unfair dismissal if the employee had been with you for a month or more.

Be careful in how you dismiss an employee who has been with you for less than one year in case he or she can claim breach of contract. The statutory minimum notice can be added to the dismissal date for the purpose of the calculation.

You are normally automatically guilty of unfair dismissal if you fail to follow a fair procedure. From 6 April 2009, there is no longer a statutory procedure that you must follow. Instead you should take fair and reasonable steps in accordance with a code of practice published by ACAS. The ACAS code is not legally enforceable but any Employment Tribunal will take into account whether you have followed its provisions.