One common scam I encounter is where a business receives an official-looking letter that looks like they need to pay a fee of some sort. Usually, the letter is for something like a "Tax Clearance Certificate" or "Certificate of Good Standing." These are things that exist, but not something a business would normally need to request.
The letter makes it looks like you need to have this item. The trick of it is that they actually do give you the certificate, so I guess it's not technically illegal? I don't know. I see it most frequently in California, but it happens to businesses everywhere.
Another scam that I've encountered: Your office manager gets a phone call from your "printer company" and they tell you it's time for your printer ink delivery. A bit of fast talking later, you've paid $500 for some low quality printer ink to be shipped to you. It works because you probably do have a printer company who sends you ink if you rent your office equipment. If you call and ask for a refund, they'll tell you "Sally, the office manager approved this purchase. We told her we weren't your normal printer company. Our ink is high quality." But they will generally take back the product and refund you. Again - not illegal, because they did actually deliver the goods, and they avoid issues by accepting refunds. In large companies, this type of purchase falls through the cracks and goes unnoticed.
These aren't big number scams on an individual basis. They're designed in a way to stop the victim from thinking too much about it. The amounts are relatively low, the product seemingly legitimate. Most people will either not notice the scam, or if they do notice, they'll let it go because it's not worth pursuing.