Marvin OnumonuResearch from Microsoft found 71% of UK workers used unapproved consumer artificial intelligence (AI) tools at work, and over half continued weekly.
Employees said they used consumer AI assistants to draft and reply to work communications, prepare reports and presentations, and do finance tasks.
Only 32% were concerned about privacy of company or customer data, and just 29% worried about IT security.
Most workers said they turned to shadow AI for convenience, with 41% saying it was what they were used to in their personal life.
Another 28% said their company did not provide an approved option.
Darren Hardman, CEO at Microsoft UK & Ireland, said: “UK workers are embracing AI like never before, unlocking new levels of productivity and creativity.
“But enthusiasm alone isn’t enough. Businesses must ensure the AI tools in use are built for the workplace, not just the living room.
“The message is clear: only enterprise-grade AI delivers the functionality that employees want, wrapped in the privacy and security every organisation demands.”
Workers using generative AI assistants reported saving on average 7.75 hours each week on admin.
Dr Chris Brauer, director of innovation at Goldsmiths, University of London, said this added up to 12.1 billion hours a year across the UK economy, worth about £208bn of workers’ time.
Use was highest in IT and telecoms, sales, media and marketing, architecture and engineering, and finance and insurance.
When asked how they would use time saved by AI, 37% wanted a better work/life balance, 31% planned to develop new skills, and 28% said they would focus on more meaningful work.
57% of employees described themselves as optimistic, excited or confident, up from 34% in January.
The share of workers who said they didn’t know where to start with AI fell from 44% to 36%.
More workers said they understood why their company was using AI, up from 24% to 43%, and more saw AI as essential to business success, up to 39% from 18%.
Microsoft’s Global Work Trend Index found 82% of business leaders saw this year as a turning point for AI, and 46% were already using AI agents to automate workflows.
Employees in frontier firms, those furthest ahead in adopting AI, were almost twice as likely to say their organisation was thriving.
