Set up a separate checking account even if you are operating as a sole proprietorship. This will make it easier for you and/or your accountant to track and manage your business expenses. Also, request a debit or credit card in the name of your business. Sometimes it's easier or faster making purchases with a credit card than writing a check and having a business card will again help you keep your business and personal expenses separate. Business account checks can run about $100 from the bank. Look for printing companies that allow you to order direct or buy check stock and use an accounting software package to print your own. It's a little less convenient if you're making purchases but it's a workable solution.
Get to know some of the banking representatives in the local branch of your bank. If ever you need personal assistance in some sticky situation, they can often be more helpful in resolving problems for you than the customer service reps at the bank's call center. You may also consider getting a small business loan to help finance some of your start up costs. Don't leave large balances in non-interest bearing accounts.
The bank will need certain documents to open a business account for you. Their requirements could include copies of your Fictitious Business Name Statement, Articles of Incorporation or Organization filed with the Secretary of State, and your LLC Operating or Partnership Agreement or Bylaws. Call the bank in advance, let them know the legal form of your business and ask what documents they will need.