That suggests around 4.9m adults in the UK currently use pirated TV services, such as Kodi boxes, Amazon Fire Chipped Sticks or illegal streaming apps on smart devices.
Based on responses from more than 2,000 UK consumers, research firm YouGov also revealed that adoption of these platforms is especially high among millennials, with consumers aged 18 to 34 accounting for 37% of the total, or 1.8m people.
Furthermore, almost a fifth (17%) of users of these platforms – around 830,000 people – have already cancelled at least one paid-for TV provider and around a third (31%) expect to cancel their subscriptions over the next 12 months.
And in another blow to pay TV providers, YouGov established in its Illegal Streaming study that consumers who are not yet using pirated platforms pose an even greater challenge to subscription services.
According to its findings, around 2.6m non-users (6%) expect to start accessing pirated streaming platforms in the future, with about 400,000 doing so within the next three months.
And half (49%) of these consumers expect that they will cancel a TV subscription within 12 months of obtaining a pirated device.
"Since Kodi boxes, Amazon Fire TV Chipped Sticks, and 'illegal' streaming apps entered the mainstream around 12 months ago, subscription TV services have come under significant pressure. Our research indicates that things are only going to get worse in the coming year," said Russell Feldman, YouGov's Director of Digital, Media and Technology.
"Not only are those currently using these platforms starting to end their subscriptions to paid-for TV services, but they are also starting to recommending them to non-users and showing them how to use these services," he added.
"While we have started to see the damage this is causing to paid-for subscriptions – notably for sports and film channels – the indications are that this is just the beginning."
Data sourced from YouGov; additional content by WARC staff