Australia has enacted a world-first ban on social media for users aged under 16, causing millions of children and teenagers to lose access to their accounts.

Facebook, Instagram, Threads, X, YouTube, Snapchat, Reddit, Kick, Twitch and TikTok are expected to have taken steps from Wednesday to remove accounts held by users under 16 years of age in Australia and prevent those teens from registering new accounts.

Platforms that do not comply risk fines of up to $49.5m. There have been some teething problems with the ban’s implementation. All listed platforms apart from X had confirmed by Tuesday they would comply with the ban. 

The e-Safety commissioner, Julie Inman Grant, said it had recently had a conversation with X about how it would comply, but the company had not communicated its policy to users.

Children had spent the past few weeks undertaking age assurance checks, swapping phone numbers and preparing for their accounts to be deactivated.

The Australian chief executive and co-founder of the age assurance service k-ID, Kieran Donovan, said his service had conducted hundreds of thousands of age checks in the past few weeks. The k-ID service was being used by Snapchat among others.

The Australian prime minister, Anthony Albanese, said in an opinion piece on Sunday: “From the beginning, we’ve acknowledged this process won’t be 100% perfect. But the message this law sends will be 100% clear … Australia sets the legal drinking age at 18 because our society recognises the ­benefits to the individual and the community of such an ­approach.

The ban has garnered worldwide attention, with several nations indicating they will adopt a ban of their own, including Malaysia, Denmark and Norway. The European Union passed a resolution to adopt similar restrictions, while a spokesperson for the British government said it was “closely monitoring Australia’s approach to age restrictions”.