You can comingle if you are a sole-proprietorship. You didn't state your business' entity structure. If you have a Corporation, you can just do a Corporate Reimbursement. It's a simple form you turn into your Corporation at the end of a quarter (I do it annually). Any time you (as the employee) use your personal credit card for a business expense (automatic monthly deductions for high-speed internet access, for instance, if you have a website or make money on eBay), you write the date, amount, and purpose on your reimbursement form. If a large purchase, you would also submit a receipt. It's a bit weird, because I am every Officer, so I submit a form signed by me to a Corporation for approval where I also sign it to approve it! The Annual Meeting has me feeing like I have multiple personalities (although it's basically just a fill-in-the-blank form with me signing my name at various parts). The Employee Reimbursement Form creates the separateness that stops the comingling problems should you ever be audited or have to show your books in court.
_________________
"A deal is only as good as the quality of your Contracts." --Me
[ Edited by LeaseOptionKing on Date 02/15/2008 ]