If you are doing work different from that of a worker of the opposite sex in the same establishment, or at another establishment where common terms and conditions apply, but the different jobs have been rated as equivalent under a job evaluation scheme, you are entitled to equal pay.
There has to be someone of the opposite sex in the same employment, with whom you can compare yourself (a 'comparator'). Differences such as payment for extra responsibilities are permitted, providing the differences are not related to the sex of the worker.
For claims made before 4 October 2009, based partly or completely on events which took place before 6 April 2009, you must have followed the statutory grievance procedure first, giving your employer 28 days to respond. Otherwise, the employment tribunal may refuse to hear your claim. This will no longer apply to equal pay claims lodged from 4 October 2009.
The law applies to all workers, regardless of age.