1. Equality

2. Equal treatment
Employers have an obligation to give men and women equal treatment in the terms and conditions of their employment contract if they are employed to do:
'like work' - work that is the same or broadly similar
work rated as equivalent under a job evaluation study
work found to be of equal value in terms of effort, skill or decision making.

3. S 1(4) equal pay act
A woman is to be regarded as employed on like work with men if, but only if, her work and theirs is of the same or a broadly similar nature, and the differences (if any) between the things she does and the things they do are not of practical importance in relation to terms and conditions of employment ; and accordingly in comparing her work with theirs regard shall be had to the frequency or otherwise with which any such differences occur in practice as well as to the nature and extent of the differences.

4. Like Work
Equal pay: "Trivial differences" should be disregarded in determining whether there is like work
Capper Pass v Lawton, the EAT held that in determining whether a woman and a man are employed on broadly similar work, Industrial Tribunals should disregard "trivial differences or differences not likely in the real world to be reflected in terms and conditions of employment".
Dugdale and others v Kraft Foods Ltd, the EAT held that the time that the work is performed should also be disregarded when considering whether jobs constitute like work within the s.1(4) definition.

5. Comparator
Employees can compare any terms in the contract of employment with the equivalent terms in a comparators contract
A comparator is an employee of the opposite sex working for the same employer, doing like work of equal value.
However, an employer may defend a claim if they show the reason for the difference is due to a genuine factor and not based on the sex of the employee.

6. E Coomes (Holdings) Ltd v Shields, the Court of Appeal held that S1 (4) Equal Pay Act requires comparison to be made not between contractual obligations of the man and the woman, but between the things that each actually does and the frequency with which they are done.

7. Equal Terms
Employees are also entitled to know how their pay is made up.
For example, if there is a bonus system, everyone should know how to earn bonuses and how they are calculated.
The Equality Act 2010 makes it unlawful to prevent employees from having discussions to establish if there are differences in pay.
However, an employer can require their employees to keep pay rates confidential from people outside of the workplace.

8. Equal Terms
The equal terms can cover all aspects of pay and benefits, including:
basic pay
overtime rates
performance related benefits
hours of work
access to pension schemes
non monetary terms
annual leave entitlements.

9. What can you do?
An employee who thinks they are not receiving equal pay can write to their employer asking for information that will help them establish whether there is a pay difference and if so the reasons for the difference.
If an employee cannot resolve the problem informally or through the formal grievance procedure, they may complain to an employment tribunal under the Equality Act 2010 while still working in the job or up to six months after leaving the employment to which your claim relates.
Since 1st October 2014 employers who lose equal pay claims could be forced to conduct an equal pay audit and publish the results.