Fibre broadband specialists Glide found that 5% of businesses experience internet loss multiple time a day and 12% lose connection at least once every single day.
On average, workers said it takes 107 minutes to reconnect to the internet, meaning millions of hours of internet downtime across workplaces in the UK.
Glasgow was named the worst city in the UK for internet connectivity, with over a quarter (26%) of workers claiming the connection in their workplace goes down at least once a day. Bristol (20%), Southampton (18%), London (14%) and Cardiff (13%) completed the top five.
Unsurprisingly, IT workers were the least affected by the issue, with 40% claiming their businesses' internet never loses connection, followed closely by HR and recruitment employees (38%) and the self-employed (36%).
Legal workers appear to be the worst affected with one in seven workers claiming they lose connection multiple times a day.
Overall, just 30% of those surveyed said their internet never loses connection.
Glide CTO, Ben King, said: "It's shocking to see just how many hours a year workers are losing due to the internet being down. With millions of offices across the country dependent on an internet connection to run, it really is worth investing in a fast, reliable and assured network to support your business needs."