The U.S. Supreme Court agreed on Wednesday to hear a bid by TikTok and its China-based parent company ByteDance to block a law intended to force the sale of the short-video app by January 19 or face a ban on national security grounds. The highest U.S. court did not immediately act on a request for an injunction to halt the looming ban.

Here is what will likely happen next for TikTok.

The U.S. Supreme Court will hear arguments on January 10, just over a week before the ban is due to take effect on January 19. TikTok and its parent ByteDance aim to block a U.S. law passed in April that would force ByteDance to divest of TikTok or face the ban. TikTok also has asked that the court issue an injunction to put the ban on hold while the legal process plays out, but the court has not yet acted on that request.

The social media company has argued that the law would harm free speech. A three-judge panel of the U.S. Court of Appeals for the District of Columbia ruled in favour of the government on December 6, citing national security considerations related to China. Last year, TikTok took similar legal actions to stop a ban on the app in the state of Montana, where a preliminary injunction was granted.

How did this start, and how long will it take?

In August 2020, then-President Donald Trump sought to ban both TikTok and Chinese-owned WeChat, but was blocked by courts. In June 2021, President Joe Biden withdrew a series of Trump-era executive orders that sought to ban new downloads of WeChat and TikTok. However, legislators later advanced a bill that compelled ByteDance to divest or face a ban. It passed with wide margins in both the U.S. House of Representatives and the U.S. Senate.

To be considered a qualified divestiture, the president must determine TikTok is no longer controlled by and would have no operational relationship with a Chinese entity. When Biden signed the bill in April, a 270-day clock started. That clock ends on January 19, but the process could be extended by court review.

Does Trump have a role here?

Trump becomes president on January 20, the day after the U.S. law indicates a ban would start. If Biden certifies a path to a qualified divestiture has been identified, there is evidence of "significant" progress toward a sale and there are legally binding agreements in place, he can authorise an additional 90 days for any deal to be finalised.

The additional time would throw the final decision to Trump, who has said he has a "warm spot" for TikTok and will not allow short video service, which is used by 170 million Americans, to be banned. If the Supreme Court does not halt the law before it takes effect, it is not clear how Trump, once in office, would be able to affect the matter. TikTok in court papers raised the possibility that the new administration would "pause enforcement" or seek to mitigate its potential consequences, although at least one senator has noted that Trump cannot ignore the TikTok law.

U.S. tech companies could face billions of dollars in fines if they allowed users to access TikTok after January 19 and even if Trump said he would not enforce the law, they could face potential risks from others who might seek to enforce it.

Will TikTok change at all?

The TikTok app should not change for its U.S. users between now and January 19.

What does the Chinese government say?

China has a list of technologies that would need Chinese government approval before they are exported. Experts said TikTok's recommendation algorithm would fall under the list, making divestment very difficult for ByteDance.