Facebook and Instagram began shutting down half a million accounts of users under 16 years old on Thursday as the deadline for Australia’s social media ban looms.

The under-16s social media ban is due to take effect from 10 December, but Meta alerted users last month that it would begin shutting down accounts from 4 December.

The eSafety commissioner reported in February that there are approximately 150,000 Facebook accounts and 350,000 Instagram accounts held by people the platform understands to be between 13 and 15 years old.

From Thursday, Meta will also begin blocking the creation of new accounts for under-16 users in Australia.

“While we are working hard to remove all users who we understand to be under the age of 16 by 10 December, compliance with the law will be an ongoing and multilayered process,” a Meta spokesperson said.

“If you’re under 16, you can still preserve and download your digital history across Instagram, Threads, and Facebook.

“Before you turn 16, we will notify you that you will soon be allowed to regain access to these platforms, and your content will be restored exactly as you left it.”

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Under 16s will also no longer be able to hold an account on Threads due to the need to have an Instagram account to use Threads.

Meta has not disclosed the number of Threads users, but it would be a subset of the number of Instagram account holders.

Last month Meta began informing users it understood to be under 16 of the pending account deactivation, and appeals methods for those it wrongly identified as being under 16.

The communications minister, Anika Wells, told the National Press Club on Wednesday that if a child has a social media account on 10 December “then that platform is breaking the law”, but acknowledged it would take time for “the age assurance sieve” to filter out existing accounts and stop new accounts being created.

“Most parents, carers and teachers I talk to don’t expect perfection, but what they do say to me is ‘Thank you for trying this – do not back down!’” she said.

“Increasing the minimum age to have a social media account is not a cure, it is a treatment plan. And this is not set and forget. We can’t be static in dynamic environments – because the tech sure isn’t.”

The platforms will face potential fines of $49.5m for failing to take reasonable steps to keep under 16s from holding accounts.

The eSafety commissioner, Julie Inman Grant, told Senate estimates on Tuesday night she will be watching the platforms come 10 December but will be taking a “graduated risk and outcomes-based approach to compliance and enforcement, focusing on platforms with the highest proportion of underage users”.

Facebook, Instagram, Threads, TikTok, Snapchat, X, Reddit, Kick, Twitch and YouTube have all been identified by the government as needing to implement the ban by next week.

All companies apart from X and Reddit have said they will comply with the ban. Both were approached for comment.

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