TikTok is preparing to potentially make the app unavailable to its 170 million American users on Sunday, the same day a U.S. ban is set to go into effect, according to a person with knowledge of the company’s planning who spoke with NBC News. A law signed by President Joe Biden in April requires TikTok to divest from its Chinese ownership and sell to a U.S. company or it will be shut down. If the Supreme Court declares the law unconstitutional before then, TikTok can continue to exist as it is today.  But a final decision has not been made by TikTok on what will happen if the Supreme Court rules against the company, according to the person with knowledge of the discussions, who spoke on the condition of anonymity because they were not authorized to speak publicly. Active conversations — including phone calls and meetings — were ongoing as of midday on Wednesday, the person said. A Tuesday report from The Information said if the justices uphold the law, the app will go dark rather than allow people already on the app to continue using it, citing two unnamed sources it said were familiar with TikTok’s plans.  Another option being discussed, according to the person who spoke with NBC News, is the potential for content to still be viewable in TikTok for users who have the application, though the app would no longer receive updates. It would be unavailable for new downloads in any app stores in the U.S., and the app would stop working over time because it would not be able to receive bug fixes and updates.  Noel Francisco, an attorney for TikTok, told the Supreme Court on Friday that to his understanding the app would “go dark” on Jan. 19 if the company lost the case. “Essentially, the platform shuts down,” Francisco said.  That is what happened in India when TikTok was banned there on June 29, 2020. Nikhil Pahwa, who founded the tech policy publication MediaNama in India, told NBC News that the app shut down the night the ban went into effect.  “By morning, we found that TikTok wasn’t accessible,” Pahwa said. “So the effect was immediate. It was just — one evening access was just cut off. Users had nowhere to go. Brands that were advertising on TikTok had nowhere to go.” For Americans visiting India, opening the TikTok app on their phone results in a notification that says “Our services are not available in your country or region.” Pahwa said that for Indian users, the mobile app doesn’t work and clicking on a TikTok link on a desktop computer results in “a simple landing page that says that the app is no longer available in India.” “It had 200 million internet users in India at that time, and so when the ban happened, they were taken aback, they didn’t know what to do. They had to find somewhere to go,” he said. “Over the years, what’s happened is that Instagram emerged as the one that won. It’s where brands have migrated, it’s where users have built profiles. Many users weren’t able to recreate the success they had on TikTok.” TikTok Jan 12 TikTok could be banned this month. Here's what users can do to prepare TikTok Jan 10 The Supreme Court is considering a possible TikTok ban. Here's what to know Social Media 9 hours ago Americans get warm welcome to RedNote ahead of potential TikTok ban Within two months of the TikTok ban in India, Instagram rolled out its TikTok competitor Reels and YouTube released its competitor Shorts. They are also the primary alternative platforms for short-form video content in the U.S., although Americans have flocked to a Chinese app called RedNote in recent days, pushing it to the top of Apple’s App Store. India has banned almost 500 Chinese apps so far, Pahwa said. He said he is unable to access TikTok with a virtual private network or VPN, which has been floated as a way to get around the ban by some U.S. users.  TikTok isn’t just a source for entertainment. It’s a place where many users make money. Some of them have full-time careers based on TikTok, while companies also use TikTok for marketing. Whether the app goes dark immediately or keeps working but degrades over time will affect how creators and brands use the platform.  Will Trowbridge, the CEO of creative agency Saylor, works with clients like the Walt Disney Company on TikTok content. Saylor has also worked with NBCUniversal, the company that owns NBC News. Trowbridge said that even if TikTok doesn’t immediately go away on Jan. 19, remaining available on phones that already have the app downloaded, at least one of his clients doesn’t want to post anymore. Some are concerned that the app would become more prone to security risks, like hacking, if it isn’t able to receive updates or support.  “They’re just stopping because they don’t want to risk it, and they don’t want to be part of that kind of decline of the app,” Trowbridge said. “Everyone has an action plan. They don’t want to talk about it, because they don’t want to face the reality of what it would mean.” This story first appeared on NBCNews.com. More from NBC News: Meta’s pivot to the right sparks boycotts and a user exodus Department of Transportation sues Southwest for ‘chronically delayed flights’ Food safety advocates expect a smooth transition away from the newly banned Red No. 3