Snapchat is about to begin alerting some users that their accounts will be deactivated when Australia’s under-16s social media ban takes effect from 10 December.

Users that the platform assesses are likely to be aged under 16 were due to begin getting notifications about the ban this week in-app, via email or SMS.

Snapchat will use behavioural signals based on account activity to estimate ages, in addition to those who have self-declared to be under 16, to build a pool of affected accounts.

Snap Inc, the app’s parent company, told a Senate inquiry last month it believes about 440,000 users in Australia are aged between 13 and 15.

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If Snapchat flags a user as under 16, but they are not, they will need to go through age-assurance methods to remain on the platform. Users will be presented with a prompt stating “verify your age” in the app to begin the process.

Age can be verified by ConnectID via an Australian bank account, by checking a government ID such as passport or driver licence, or through facial age estimation. The latter will require users to take a selfie that is analysed using technology provided by age-assurance company k-ID.

Users under 16 will be given the option before 10 December to download data such as chats, memories and videos. Their accounts will be locked from 10 December until the user turns 16 and chooses to reactivate their account by verifying their age.

Accounts that are locked for more than three years and not verified will be deleted.

Snapchat disagrees that it should be covered by the ban – it has argued the primary purpose of Snapchat is for messaging, which is otherwise exempt – but it will comply with the ban.

“Snapchat is and has always been a visual messaging app, primarily used for connection with your closest friends and family,” a spokesperson said.

“We know that for teens, maintaining friendships is a key contributor to happiness and well-being and are deeply saddened that young Aussies can no longer connect with their nearest and dearest via Snapchat.

“However, even though we strongly disagree with the government’s assessment … we will disable accounts for users under 16 from December 10.”

Snap is the second of the platforms to announce how the ban will be implemented, after Facebook and Instagram parent company Meta last week started alerting affected users.

TikTok and Kick have said they will comply with the ban but have yet to outline what steps they will take to implement it.

Reddit, Twitch, X, and YouTube have yet to state their position on the ban, and whether they will comply.