TikTok has removed a number of videos after a BBC investigation showed creators were posting anti-Trump material without disclosing that they were paid for by a marketing company.
The company, Bigtent Creative, funds skits and memes to persuade people to register, such as mixing rapper Cardi B's WAP song with a message from her telling people to vote.
Some of the videos it has paid for are non-partisan, but others call for President Trump to be voted out of office and in none of the videos do the creators disclose that they have been paid.
TikTok bans political ads and requires people to declare paid-for content. When we showed TikTok what we found, the company took several TikToks down - these had already got hundreds of thousands of views.
Guidelines from the US Federal Trade Commission (FTC) stipulate content creators should always disclose paid partnerships, usually by using '#ad' in the caption.
A TikTok spokesperson said: "These guidelines also apply to paid content by influencers, and we rely on influencers and marketers to follow FTC guidelines.
"We remove paid influencer content that's not disclosed as such as we become aware of it and are now taking action on this."
With two weeks until the US election, the competition for the youth vote is fierce and the drive to get first-time voters to register has intensified.
Potentially millions of young TikTok users will not understand that some of the fun, quirky skits they are seeing are being paid for or supported by political interests.