Yes. Flat Fee MLS Listings are not only legal, but suggested by authorities no less than the US Federal Trade Commission, US Department of Justice, and nearly every Consumer Advocacy Organization.
If you are asking this question, it may mean that you have encountered a traditional agent who is trying to scare you into signing a huge commission traditional listing agreement. Not only have we been doing flat fee MLS listings for over 20 years, but our system is designed for the first time home seller who doesn't know anything about real estate.
These agents will often tell you that real estate is substantially more complicated than both rocket science and brain surgery! They will insist that you will mess up and terrible things will happen. For the truth, have you read what our past customers have written about the flat fee home selling process? Check out home sellers' experiences here.
Some agents can't justify the huge commission they charge, and will resort to scare tactics and misinformation such as this. Don't let them take away your opportunity to save the huge commission.