Australia will not require social media giants to verify the ages of all users under its ban on under-16s using the platforms, Canberra said Tuesday.
But platforms like Facebook, Snapchat, TikTok and YouTube are expected to take "reasonable steps" to stop children from accessing the apps, it said.
Australia has been a leader in global efforts to prevent internet harm, but current legislation offers almost no details on how the ban will be enforced -- prompting concern among experts that it will simply be a symbolic piece of unenforceable legislation.
Social media companies have also described the laws as "vague", "problematic" and "rushed".
Communications Minister Anika Wells said on Tuesday social media groups would need to take "reasonable steps" to detect and deactivate underage users.
"We cannot control the ocean, but we can police the sharks and today we're making clear to the rest of the world how we can do this," she said.
"There is no excuse for social media platforms to fail to meet their obligations under the new laws," she added.
Tuesday's long-awaited regulatory guidelines said social media platforms will need to take a "multilayered" approach to age checking.
But the head of Australia's online regulator, the eSafety Commission, accepted there was "no one-size-fits-all solution" to actually enforcing the world-first legislation.
"By taking a layered or 'waterfall' approach... platforms can manage the risks associated with any errors in age inference or estimation," Inman Grant said.
"Platforms won't have to age verify every Australian user to comply," Grant said.
The eSafety Commission will be able to fine social media companies up to Aus$49.5 million for failing to comply with the rules.
An independent study ordered by the Australian government found this month that age checking can be done "privately, efficiently and effectively", though it admitted no single solution would fit all contexts.
The regulator has also introduced a number of rules taking effect in Australia in the coming months to protect children from "lawful but awful" content, including online pornography and AI chatbots capable of sexually explicit conversations.
This week, gaming giant Roblox Corp agreed to curb the risk of adults grooming children on its platform in Australia.
