Every employee who works for an employer has a contract of employment.
By law, your employer must at least give you a written statement of particulars as soon as you start work. This must include:
names of the employer and employee
date the employment began, and the date continuous employment began (if different)
place or places of work
details of any probationary period
days and hours of work and whether they may be varied and how
holiday and sick pay entitlement, including information on public holidays
a job title or description
details of pay and frequency of pay
where employment is not intended to be permanent, the period it is expected to continue or its fixed term
any pension provision
any collective agreements that affect employment
information on working outside the UK if that is appropriate
information about training entitlement provided by the employer
This statement of particulars is usually included in a contract of employment, as written contracts can avoid confusion by clearly setting out both parties rights and obligations.
As well as the required information, contracts often include information on benefits, disciplinary and grievance procedures, restrictive covenants and provisions about confidential information and intellectual property. Less common terms might include shift patterns, medical requirements, provisions to alter the place of work and a requirement to work only for the employer.
Even if your employer has not given you a written contract, you have a legally binding agreement from the time you accept an employment offer. You also have expectations set by conduct in your working relationship.
Whether your contract is in writing or not, there are also terms implied by law (such as the Employment Rights Act 1996 and the Equality Act 2010) that apply to all employment relationships.