The Birmingham council workers’ recent victory means workers now have six-years to make an equal pay claim in the high court. In other words, they are not limited to making such a claim within a six-month window to an employment tribunal, which Birmingham Council were arguing should be the case under its interpretation of existing legislation.

As women make up more than half the UK workforce, and previous EU surveys have shown the country as having one of the highest pay gaps between men and women, will this open the floodgates to other claims going back six years, especially in traditionally male dominated industries? What actually amounts to “pay” for the purposes of a claim being made? And what may be on most people’s minds is how they actually find out if they are being paid less than their gender counterparts?

Laws on equal pay have existed for more than 40 years, and the latest legislation is in the Equality Act 2010. The act requires that, where men and women are employed on equal work, the terms of their contracts should also be equal, including pay. This law applies where there are differences in equality of terms between men and women, but does not apply to those persons of the same sex.

For the purposes of the act, “equality of terms” includes contractual pay, but can also embrace other terms and conditions of employment such as the provision of a company car, healthcare and other benefits – therefore, a differential of any such terms can give rise to a claim.

If you think you have been paid less than a gender counterpart, how do you find out what they are earning and how would this best be tackled with your employer? As a starting point, you need to establish who exactly you are comparing yourself with of the opposite sex.

That person should be employed on “like work”, “work related as equivalent” or “work of an equal value” basis. This person then becomes your “comparator” and must be in the “same employment” as you, meaning it must be with your employer or an associated employer.

Once you establish who your comparator is, you are entitled under the act to ask your colleagues about their pay in order to establish whether there are inequalities. However, there is no obligation on your colleague to respond and you cannot be penalised by your employer for having such discussions.

In addition, under section 138 of the act there is a questionnaire you can send to your employer to seek further information in relation your concerns about unequal pay. This is to establish whether your employer agrees with your assertion of carrying out the same role as the opposite sex, confirmation of what the pay differential amounts to, and whether there is a “material defence” to such differentials.

The types of “material defence” that could be raised by an employer include geographic locations or market forces necessitating the need to retain employees carrying out particular roles at a higher salary. An employer must show that all the differences are attributable to the reasons they provide.

As always, it is often best to approach your employer on an informal basis to see if matters can be resolved. If proceedings are ultimately necessary, you can either bring a claim in an employment tribunal at any time while you are still employed, or within six months of leaving your job.

Alternatively, after yesterday’s judgement you have six years to bring a claim in the high court, although it was specified that claims should be brought in the employment tribunal where it is still possible to do so. The fact you now also have a longer time period does, however, leave your employer exposed. Whether this will lead to a rush of historic claims remains to be seen