In the year following the UK gender pay audit, which forced private companies with more than 250 employees to make their pay figures public, you would’ve thought industries would feel compelled to do better.

But it seems that it wasn’t enough to incentivise companies to address the gender pay gap, as a BBC analysis has found 40% of private firms are reporting an even wider gap this year compared to last year.  

Virgin Atlantic, Kwik Fit and Npower all reported having a wider gap between male and female pay this year. Only 10% of private sector firms have reported their pay so far, ahead of the 4 April deadline, but already it’s not looking good.

Of the companies who had reported by Tuesday 19 February, 74% had a gap which favoured men, 14% had a pay gap favouring women, and 12% had no gap at all. 

[Read More: What progress is actually being made to close the gender pay gap?]

The gender pay gap is different to the issue of unequal pay, where women are paid less  than a man for the same job – which is illegal. 

Instead, the gender pay gap calculation looks at the difference in pay between the middle-ranking woman and the middle-ranking man in any workplace: a sum which takes into account the discrepancy between the number of senior men and senior women. 

Public sector firms must report their pay by 30 March, and charitable and private firms by 4 April. It will take time for firms to improve their figures, the government said.

Some companies have responded to their growing pay gaps. Npower, whose gap grew from 13% to 18%, attributed this to more female employees opting for a salary sacrifice benefits scheme.

The gap at car mechanics chain Kwik Fit grew from a negative gender pay gap – of minus 15.2%, which favoured women – to a positive one of 14%, favouring men. A spokeswoman told the BBC the industry had been “historically more appealing to men”, but she did say it was trying to recruit more women.

And the pay gap at Virgin Atlantic increased from 28.4% to 31%. A spokeswoman said the firm was focused on achieving diversity for all roles, including engineers and pilots. 

For some firms, such as RBS, comparable figures are unavailable, but the gap remains high – the bank reported an average gap of 36.8%, one of the biggest for a company of its size.

A spokesperson for the Government Equalities Office said: “The gender pay gap is currently at the lowest level it has ever been. However there is clearly more to be done, which is why we have made it compulsory for large businesses to declare their pay gap every year.

“Closing the gender pay gap is not a quick fix, and employers may take time to see their gap close as they implement long term action plans. It is important that they continue to work at this, and we are confident that the majority of businesses are now treating this as a priority.”