Credit union. 
 
A good friend just changed from his "big" bank to the same credit union after this incident a couple weeks ago. 
 
He brings in a check to cash. It was a few thousand $, but no bigger than many other checks he had cashed there (he uses cash to buy antiques). He has banked there for many years, knows all the tellers, knows the manager. The teller sees something on her computer screen and goes to get the manager. The manager comes over and tells my friend he can't cash that check because he doesn't have enough money in his personal account to cover it in case it bounces. 
 
He tells them to look at his business account, where he has many times that amount. Manager says well, the check isn't made out to your business, it's made out to you personally.  He stared at the manager for a minute, then the manager says, OK, deposit the check in his business account, then write himself a check from the business account to get the cash. My friend is not carrying around blank checks so that's not an answer. 
 
He asks why this is a problem when he has done the same thing many times over the years. The manager shrugs and says the computer won't let us cash it because you don't have that amount available in your personal account. 
 
So he closed his accounts and moved to the credit union, where they told him that scenario would not cause any problems, they would be happy to accommodate him, and by the way, could he use a $50,000 line of credit for his business?