Brands are expected to cut more than £1bn of digital advertising spending due to the UK’s ban on social media for under-16s, with streaming services tipped to benefit as advertisers try to reach large audiences of teenagers.

The ban, due to come into force early next year, will leave UK advertisers scrambling to reassess marketing plans as millions of under-16s effectively disappear as a demographic that can be marketed to on platforms including Facebook, Instagram, Snapchat and YouTube.

Analysts at eMarketer cut their existing forecast for UK digital advertising spend for 2027 by £1.3bn to £17bn after assessing the ban’s likely impact.

Research conducted last month by Beano Brain, the kids and family research agency, found that among seven- to 14-year-olds a third said that YouTube ads and YouTubers were how they found out about new things that they wanted to buy. A quarter of those surveyed cited TikTok videos while 22% said TV ads influenced their buying decisions.

Helenor Gilmour, head of the DC Thomson-owned agency, said teenagers and younger children will continue to see some social media through “parallel me time” with their parents but streaming services could pick up business as a result of the ban.

“There is certainly going to be a period of readjustment,” said Gilmour. “Netflix, Amazon Prime Video and Disney+ have ad tiers now, and kids are all over those platforms. We will see a big shift [in ad spend] moving in that direction, they will be big winners and soak up quite a bit of the YouTube revenue.

“Traditional TV will also benefit around big family-friendly event shows such as I’m A Celebrity and Britain’s Got Talent.”

In the four years since Amazon, Disney+ and Netflix introduced advertising, the number of UK viewers on subscriptions that include ads has hit 27 million, reaching a scale increasingly attractive for brands.

James Kirkham, a brand strategist who has worked with clients including JD Sports, Netflix and Chelsea Football Club, said the ban is an opportunity to channel marketing spend into creating “cultural cornerstones” – reaching young people through sport or via their schools.

“The notion that advertising money is going to evaporate is mad, the ban won’t mean shrinking budgets, it is going to go somewhere,” he said. “We are always saying to clients: ‘Does it survive the scroll?’ Most of the ads in feeds are gone from the consumers’ mind in 60 seconds.”

Advertisers targeting young people have long had to operate under tight regulations, dating back at least as far as the TV junk food ad ban around children’s shows and programmes of “particular appeal” to under-16s, introduced by the communications regulator Ofcom in 2006.

Earlier this year, the UK advertising watchdog began cracking down on ads featuring junk food on TV before 9pm, and in paid online advertising at any time of the day, while billboards and posters within 100 metres of a school or sports centre have not been allowed to display junk food messaging for a decade.

“[Large] advertisers and the industry won’t be scared by the ban,” said Joseph Petyan, chief executive of WPP-owned agency VML. “We operate in a very regulated environment already, which is the right thing to do if you want to build a trusted brand.

“For those that are building a brand in a social media environment there will be a reassessment about what you do, but the large majority aren’t targeting kids in social media.”

Facebook-owner Meta, Snapchat and Google’s YouTube have all criticised the ban, which goes further than the one introduced in Australia earlier this year, arguing that it will send teenagers to unregulated alternative platforms.

The eMarketer market research company hasargued that digital advertising will quickly recover as brands get to grips with the new marketing landscape, and big tech companies double down on targeting older users of social media.

Bill Fisher, principal analyst at eMarketer, said: “The impact of a social ban would be concentrated in the first year after implementation, reflecting the immediate effect of lower teen usage, weaker targeting tied to minors and advertiser caution around the changing regulatory environment.

“Growth [will] actually rebound the following year. Social platforms will likely respond by shifting further toward adult monetisation, creator-led discovery, private messaging and commerce-oriented formats.”