Tellers asking how to handle:
Customer has a only a sole proprietorship business account. They want to deposit and/or cash checks made out to them personally.

Thoughts?

We have no problem doing that at our bank. Customer owns the account and the DBA is so he can deposit his business checks. He is the owner and responsible for checks payable to him or his company.

We are also ok with this but we have discovered there are a few sole props that are set up incorrectly so we fix them as we discover them. Also, many people out there don't really know what a sole prop is and try to set one up with an assumed business name without registering the name with the Secretary of State.

Our rule of thumb is that a member can deposit/cash personal checks off of a business/sole but members can't deposit/cash business/sole checks off of a personal.

The key to this is "personal checks." I can cash checks made out to me. I cannot (or you shouldn't allow) me to cash checks made out to Dickinson Plumbing (or any dba name). There are a number of reasons why. Here are a few:
1. Tax evasion (I don't want the IRS to see the income);
2. Embezzlement (maybe I have an agreement with an employee to share x% of income. If I cash checks, the employee may not know about the income and they aren't going through the account, so there is no record of it.

If a business owner wants cash, they can deposit the check and then make a cash withdrawal. If they have a problem with that, ask them why?