Women are still under represented and underpaid in the IT industry, a new report from Deloitte has shown.

In its TMT Predictions 2016 report, the company found that under a quarter of jobs in IT in developed countries would be held by women by the end of 2016, which it says is at best the same as the figure for 2015, and possibly lower.

The issue, which the firm says has been recognised since at least 2005, costs the global IT industry billions annually. In the UK alone the cost is $4bn every year. It says that the cost means having a roughly 50/50 gender split in the industry "seems a reasonable goal over the long term".

Regina Moran, CEO Fujitsu UKI, said that the predictions "are bad news for our industry," and "gender balance isn’t a ‘nice to have’, it’s a must have."

Between 2010 and 2015 the UK was in fact one of the countries that saw a small rise in females in the industry. There was an increase from 17% to 18% in women who held some of the 1.2m IT jobs in the UK. By comparison, the US, which has 5m IT jobs, saw a decline from 25%to 24%.

"It is only through a diverse workforce that tech companies like Fujitsu will be able to continue to innovate and grow. Women make up a large proportion of our customers both professionally and personally – so neglecting women in the workforce will be a costly mistake," said Moran.

One of the key issues is the number of women coming through the education system with the right skills. Just 17.1% of computer science students in the UK were women in the educational year 2013/14, and 18% of computer science graduates in the US were women in 2013.

The report notes that in 1985 that number in the US was 37%. Moran called on IT stakeholders to encourage women in STEM subjects to try and solve this problem.

Women are also less likely to apply for IT jobs. Only one in 20 applications for IT jobs is female. Lauren Ingram, Head of Marketing and digital agency Cult LDN said: "I was lucky enough to get onto a 6 month mentoring programme (Girls in Tech UK), which was designed to give young women the confidence to apply for more senior roles in the industry. Not every young woman has access to this one-on-one coaching, but this is something we can aim to change. It’s every woman and man’s responsibility to ‘send the elevator down’ and help younger women progress in IT."

The report found that even when women do get into the IT industry, they are paid less than their male colleagues. In the US a female web developer makes 79c for every dollar that a man doing the same job makes, while female systems managers are paid 87 cents to the dollar.

Women are less likely to be promoted in the IT industry too. 37% of women in IT in the UK said that they have been missed out on a promotion because of their gender, with only 14% of UK CIOs being women. Women occupy 9% of senior IT roles in the UK.

There is some good news though. Deloitte found that the IT jobs categories that have the lowest level of female representation are shrinking, while those that are more balanced are actually growing. The firms says this suggests "we may be nearing a tipping point."

It also notes that there have never been more senior women in tech, with some high profile figures providing leadership and inspiration for future generations.

Read CBR’s women in tech interview with Regina Moran here.