"If a company insists on giving you an estimate over the phone or internet instead of coming to your home, that's a bad sign. And never sign a document that has a lot of blank spaces that haven't been filled in. Another red flag? The movers are using unmarked trucks," said Anthony Giorgianni, Consumer Reports.
Consumer Reports says you should find a legitimate mover with a good reputation and get recommendations from real estate agents or from friends who have used a moving company.
The website https://www.protectyourmove.gov/ lists moving companies licensed for interstate moves.