TikTok to ‘Go Dark’ on Sunday for Its 170 Million American Users

TikTok said late Friday that its service would “go dark” for its 170 million American users on Sunday because of a ban in the United States over fears that its Chinese ownership poses a threat to national security.

The company said in a statement that “unfortunately TikTok will be forced to go dark on January 19” unless the Biden administration assures Apple, Google and other companies that they would not be punished for delivering TikTok’s services in the United States.

The statement was TikTok’s latest attempt to pressure the administration to grant it a reprieve from a law, upheld by the Supreme Court on Friday, that would effectively ban its service starting Sunday.

The law says that app stores and major cloud computing providers cannot deliver TikTok to U.S. consumers unless the company is sold by its Chinese parent company, ByteDance, to a non-Chinese owner.

TikTok did not detail what would happen on Sunday, including whether it would voluntarily shut itself down or simply cease to function because it would lose access to services it needs to stay online.

The Biden administration had earlier signaled that federal officials would not immediately take action against Apple, Google and the other companies under the law.

President Biden signed the TikTok ban bill into law in April after it passed Congress with bipartisan support. Lawmakers said Beijing could pressure ByteDance to extract sensitive data on American users or influence TikTok content to serve the Chinese government’s interests.

TikTok has said the Chinese government has no role in the company and that it has spent billions of dollars to address U.S. security concerns. ByteDance has headquarters in Beijing and is subject to China’s control.

On Friday, the Supreme Court accepted the government’s national security rationale for the law, with the majority opinion pointing to “TikTok’s scale and susceptibility to foreign adversary control, together with the vast swaths of sensitive data the platform collects.”

Lisa Monaco, the deputy attorney general, said in a statement after the Supreme Court’s ruling that the process would play out “over time.” The White House press secretary, Karine Jean-Pierre, said that enforcing the law would fall to the incoming Trump administration, which takes office on Monday.

TikTok said that those comments were not enough to satisfy other companies that they would not run afoul of the law if they continued to distribute and maintain the app. Those companies could face penalties as high as $5,000 for each TikTok user who accesses the app inside the United States after the ban takes effect.

“The statements issued today by both the Biden White House and the Department of Justice have failed to provide the necessary clarity and assurance to the service providers that are integral to maintaining TikTok’s availability to over 170 million Americans,” the company said.

The loss of that user base would be significant, but not the biggest TikTok has suffered. In 2020, it was banned in India, where it had 200 million users. As in the United States, the authorities in India cited national security concerns for their decision against TikTok.

President-elect Donald J. Trump has indicated his support for TikTok, but how his administration will proceed on the matter is unclear. He said on social media that the Supreme Court ruling must be respected.

“My decision on TikTok will be made in the not too distant future,” Mr. Trump said, “but I must have time to review the situation.”