The first daughter announced on Wednesday she would serve as an unpaid employee in the White House, responding to ethical concerns that had been raised.
"I have heard the concerns some have with my advising the president in my personal capacity while voluntarily complying with all ethics rules and I will instead serve as an unpaid employee in the White House office, subject to all of the same rules as other federal employees," she said in a statement.
Trump previously announced she was getting a West Wing office next to senior adviser Dina Powell, who serves on the National Security Council, and would be given security clearance.
However, she said at the time was not officially joining the administration, a decision that drew criticism from ethics experts.
Sources close to Ms Trump had told Politico she saw nothing unusual with the arrangement and that it was a continuation of how she has worked alongside him for several years at the Trump Organisation and on the reality TV show The Apprentice.
Trump attorney Jamie Gorelick said she would file the financial disclosures required of federal employees and will be bound by ethics rules.
In a statement, the White House said it was "pleased that Ivanka Trump has chosen to take this step in her unprecedented role as first daughter and in support of the President".
The first daughter's influence was seen soon after the election when she sat in on the then-president-elect's meeting with Japanese leader Shinzo Abe at Trump Tower.
Since then, Ms Trump, who is also the wife of Trump senior adviser Jared Kushner, has taken an increasingly high-profile in the White House, co-ordinating meetings with international leaders such as Justin Trudeau, Canada' prime minister, and Angela Merkel, the German Chancellor.
She has also accepted an invitation from Mrs Merkel to attend a women’s economic summit in Germany next month.
"She’s the most prominent woman in this (incoming) administration next to Kellyanne Conway, one of the few women in the Trump orbit," Kate Andersen Brower, author of First Women: The Grace and Power of America’s Modern First Ladies, told USA Today in January.
"Hers is the one phone call her father always takes. She's his top adviser, he respects her judgment and...she softens him a little bit."