Imagine you run a small plumbing business. You have a solid reputation, a steady stream of customers, and a four-and-a-half-star rating on Google. Then one morning you see a one-star review from a user named “HonestHomeowner22.” The review claims your team left a pipe leak that flooded a basement and refused to come back. The thing is, that never happened. You check your records, your schedule, your invoice log. No such job. After some digging, you discover the review came from an IP address linked to a competing plumbing company down the street. That competitor wrote a fake negative review to damage your business.

This scenario is more common than most people realize. And it is not just unethical—it is a lawsuit waiting to happen. Under the law, a fake negative review written by a competitor can qualify as defamation, and it can also open the door to other legal claims like tortious interference with business relations and unfair competition. Understanding how this works matters if you run a business, write reviews, or simply rely on online ratings to make purchasing decisions.

Defamation happens when someone publishes a false statement of fact that harms another person’s reputation. In the context of product or business reviews, the key issue is whether the statement is a verifiable fact or a subjective opinion. “This plumber was rude” is an opinion, even if unfair. But “this plumber flooded my basement and refused to fix it” is a factual claim. If that claim is false, and if it causes real damage—lost customers, lost revenue, harm to reputation—the person who wrote it can be held liable. When a competitor writes that fake review, the legal stakes go even higher.

The reason courts treat competitor-written fake reviews with extra seriousness is the element of malice. In defamation law, private individuals usually only need to prove negligence—that the reviewer failed to check the truth. But when the reviewer is a business competitor, the standard often shifts. A competitor who knowingly writes a false review is acting with actual malice, meaning they knew the statement was false or acted with reckless disregard for the truth. Proving malice can unlock higher damages, including punitive damages meant to punish the wrongdoer and deter others.

Beyond defamation, a fake review from a competitor can support a claim for tortious interference. This legal theory says that a person who intentionally interferes with your business relationships—by scaring off customers with lies—can be sued for the resulting losses. If a customer cancels a contract because they read the fake review, the competitor who wrote it may owe you the value of that lost contract. Similarly, many states have laws against unfair competition, which can include deceptive trade practices like posting false reviews to steal customers. The Federal Trade Commission also polices fake reviews, and a competitor caught writing them can face federal fines.

Proving that a specific competitor wrote a fake review can be tricky, but it is getting easier. Courts have allowed subpoenas to demand that review platforms like Google, Yelp, or Amazon reveal the IP addresses and account information behind anonymous reviews. Once you connect that reviewer to a competitor’s office building, home Wi-Fi, or employee email account, the case becomes much stronger. Some businesses have even hired forensic experts to analyze review timestamps, language patterns, and metadata. In one well-known case, a dentist sued a former patient who posted fake negative reviews on multiple platforms; the court awarded over $400,000 in damages.

If you suspect a competitor is writing fake negative reviews about your business, do not just get angry. Get evidence. Take screenshots of the reviews, note the dates and times, and record any suspicious patterns—like a sudden cluster of one-star reviews from newly created accounts with no other activity. Then contact a lawyer who handles defamation or business litigation. Many lawyers offer a free initial consultation, and the cost of a cease-and-desist letter is often worth it. In some cases, a single letter threatening legal action is enough to make the competitor delete the reviews and back off.

But be careful not to escalate recklessly. If you incorrectly accuse someone of writing a fake review, you could be the one facing a defamation suit. Stick to the evidence. Also remember that not every negative review is fake, even if it feels unfair. A customer with a genuine bad experience—whether or not you agree with their version of events—usually has a right to post their opinion. The law protects that. What it does not protect is deliberate lying by a competitor to damage your business.

The bottom line: fake negative reviews written by competitors are illegal and actionable. If you endure this kind of attack, you have real legal tools to fight back. And if you are the one tempted to write a fake review about a competitor, understand that the consequences can include a court judgment, public exposure, and a wrecked reputation of your own. Online reviews depend on trust. When that trust is broken by lies, the law is there to restore it.