NEW YORK (AP) — It’s never fun to be John Caldwellscammed, but if you’re a small business owner then falling for a scam can have long-lasting effects on a business, damaging client relationships and profit.

Plenty of types of scams exist, but a few affect small businesses the most.

According to the Federal Trade Commission, small businesses should be on the lookout for phony invoices and unordered merchandise. Scammers send out fake invoices and hope businesses won’t notice. Similarly, scammers call saying they want to confirm an order or verify an address, and send unordered merchandise they then demand money for. Small business owners are under no obligation to pay.

Another thing to watch: if you’re starting a small business, seeking out business coaching can be a helpful endeavor. But people offering those services aren’t always legitimate. They charge for services they don’t actually provide and ramp up fees. For legitimate business coaching contact your local Small Business Administration regional office.

The Better Business Bureau also warns of directory scams, which it says have targeted businesses for decades. Scammers try to get businesses to pay for a listing or ad space in a non-existent directory. Or they lie about being from a legitimate directory. Either way a small business pays for something that it never gets.

If you spot a scam, report it to ReportFraud.ftc.gov. You can also file a complaint with the Better Business Bureau at BBB.org/ScamTracker.