An administrative law judge says Michigan-based Quicken Loans and five affiliated companies must change rules that restrict what workers can say, how they should dress and what they should display at their desk.
The judge, David Goldman, repeatedly said many rules are "overly broad," including restrictions on posting online opinions about the workplace.
He also said employees should be told they have the right to join a union.
Some rules were upheld.
Quicken says it will appeal Goldman's decision to the National Labor Relations Board.
In a statement, Quicken said Friday that the ruling sets a "dangerous precedent" and "exceeds the boundaries of rationality."
The complaint was filed by Hugh MacEachern.
He claims he was fired by Quicken in retaliation for exploring whether to start a union.
