Amazon had told employees to delete the popular app from phones on which they use Amazon email - citing security risks from the China-owned service.
The email - obtained by the New York Times and sent to Amazon employees - says that "the TikTok app is no longer permitted on mobile devices that access Amazon email”.
It continues: "If you have TikTok on your device, you must remove it by 10-Jul to retain mobile access to Amazon email."
The move would have escalated the stakes for TikTok, which has been subject to national-security and geopolitical concerns.
Amazon is the second-largest US private employer after Walmart, with with more than 840,000 employees worldwide.
TikTok said Amazon had not communicated with them before sending the email, and added: "We still do not understand their concerns, we welcome a dialogue so we can address any issues they may have and enable their team to continue participating in our community.
"We're proud that tens of millions of Americans turn to TikTok for entertainment, inspiration, and connection, including many of the Amazon employees and contractors who have been on the frontlines of this pandemic."