We have a C Corp that I am filing taxes for.
I have some expenses that are valid business expenses, that I paid for with a personal credit card.
How do I account for those?
Yes, I realize going forward I should not do that!
The expenses should be accounted for the same way business expenses are handled when an employee pay for something that their employer will reimburse. (Think hotel room and food while on a business trip). You need to fill out some sort of reimbursement form and submit the form and receipts to the business. The company then approves the form and pays you back for the expenses. This way business and person accounts are kept separate and there is a trail of paperwork explaining payments made by the company to yourself.