Sales of CDs plummeted by 23% last year, as consumers flocked to streaming services for their music.
Just 32 million CDs were sold in 2018 - almost 100 million fewer than in 2008; and a drop of 9.6 million year-on-year.
The growth of vinyl also began to plateau, with 4.2 million records sold, a rise of just 1.6%, said the BPI.
The CDs that did sell in large quantities tended to appeal to older, non-traditional music buyers - with six of the year's top 10 albums either film soundtracks or Now compilations.
The picture is the same in America, where CD sales have fallen 80% in the last decade, from roughly 450 million to 89 million.
In a sign of the times, two of the records nominated for album of the year at the Grammys (H.E.R.'s self-titled debut and Cardi B's Invasion of Privacy) weren't even released on CD in the US - the first time that's happened since 1984.
"Lots of us have changed the way we consume music and film, and more people are streaming from Netflix or Spotify," Kim Bayley of the Entertainment Retailers Association recently told BBC Radio 5 Live.
"But I think we should remember that [physical music] is almost a £2bn business. Even HMV has sales still of a quarter of a billion pounds, so that's not a small business."
Jon Tolley, who runs the independent record shop Banquet Records argues that streaming can co-exist with vinyl and CDs.
"I don't buy it that physical music is necessarily competing with streams. We all access music and film on the internet, and that's fine and healthy and valid, but you wouldn't look at the Mona Lisa on your phone and think it's the same thing as going to see it in a gallery."
"The reason vinyl sales are at a 25-year high is because people are rejecting this part of modern society where everything is immediate and nothing means anything."
Mumford and Sons star Ben Lovett agrees. "We all use Spotify but I think we all value vinyl," he told BBC News.
"We've spent a lot more time talking about how we put our vinyl out than we have done about how we're going to stream our songs.
"We will literally talk about the weight of the vinyl, the presentation, the quality of the cut - all that stuff. People don't know how important it is to us."
Fellow musician Jack White recently told Rolling Stone he thought the CD was on the way out.
"I definitely believe the next decade is going to be streaming plus vinyl - streaming in the car and kitchen, vinyl in the living room and the den. Those will be the two formats. And I feel really good about that."
In contrast to the physical market, streaming services are flourishing.
A total of 91 billion songs were played on Spotify, Apple Music and their competitors last year - the equivalent of 1,300 songs per person in the UK - and streaming now accounts for nearly two thirds (63.6%) of all music consumption in the UK.
The popularity of on-demand music was enough to compensate for the slump in CD sales and downloads; giving the industry its fourth consecutive year of growth.
A total of 142.9 million albums were either streamed, purchased or downloaded, with an estimated retail value of £1.33 billion, said trade body the BPI.
However, it was a poor year for new talent. Anne-Marie's Speak Your Mind was the year's biggest-selling debut album, shifting 160,000 copies - but no other British debut sold more than 100,000, the threshold for a gold disc; while Jorja Smith and Giggs' debut albums both went silver, with sales in excess of 60,000 copies.
BPI chairman Geoff Taylor praised the "strong performance" of British music, but warned that the industry shouldn't become complacent.
"As we are already seeing, including with the news that HMV has gone into administration, continuing growth could be put at risk if a hard Brexit further harms consumer confidence or Government fails to ensure that all platforms using music pay fairly for it.
"If these risks are avoided, British music remains poised for further growth."
This article was updated at on 3 January, to correct the omission that Jorja Smith and Giggs both won silver discs in 2018.