The government will now have to pay back the £27m that it took in employment tribunal fees between 2012 and 2016.
Unison argued that the Employment Tribunals and the Employment Appeal Tribunal Fees Order 2013 (fees order) was not a lawful exercise of the statutory powers of the then lord chancellor, justice secretary Chris Grayling.
Under the fees order a claimant for an employment tribunal would have to pay £390 or £1,200, dependent on the type of claim being made.
A fee totaling £1,600 was required for an employment tribunal appeal for individuals wishing to challenge a previous ruling. A claim or appeal would be rejected if not accompanied by the designated fee.
The union claimed the order to be an interference of justice, as well as discriminating unfairly towards women and other protected groups.
The court unanimously allowed the appeal, considering the fees order to be unlawful under domestic and EU law, due their affect on blocking access to justice.
“The government is not above the law,” said David Prentis, Unison general secretary.
“But when ministers introduced fees they were disregarding laws many centuries old, and showing little concern for employees seeking justice following illegal treatment at work,” he continued.
“These unfair fees have let law-breaking bosses off the hook these past four years, and left badly treated staff with no choice but to put up or shut up.
“We’ll never know how many people missed out because they couldn’t afford the expense of fees.
“But at last this tax on justice has been lifted,” Prentis added.
Lord Hale concluded that the current fees were discriminatory towards women and protected groups because they make a higher proportion of the more expensive types of claims.
“As well as having a massive effect on tribunal process and claimants' ability to bring claims, this will also result in a significant hit on the court system's coffers,” said Joe Aiston, senior associate in the employment, pensions and mobility group at international law firm Taylor Wessing.
“Since the introduction of the fees, countless numbers of self-employed people have been denied access to justice because of prohibitive fees. Today’s decision brings us closer to ending this iniquity," said Simon McVicker, director of policy at the Association of Independent Professionals and the Self Employed.
“However, there are still concerns for freelancers who have to rely on tribunals to achieve clarity over their employment status – they’re costly, time-consuming and can make going about day-to-day business very challenging.
“That is why we are calling for the government to introduce a statutory definition of self-employment to end this confusion, and improve working conditions for the UK’s 4.8 million self-employed people,” he added.
“Now the government is going to have to re-think its strategy – not easy given the current pressure on legislative time because of Brexit, and also because of their greater focus on the right of workers as part of the ‘just about managing’ community,” said Richard Fox, head of employment law at law firm Kingsley Napley.
This month saw another landmark for employment rights, with the publication of the Taylor Review.