I use a Capital One Credit Card for all my business expenses when running my event photography and photo booth business in DC:

Keeping my business expense separate from my personal expenses is important for keeping me organize when tax time comes! I use Capital One for my business credit card and love the cash back rewards on my purchases! The 1.5% cash back adds up over the course of the year and I am able to reinvest that into my business or treat myself at the end of the year. When you sign up you can earn a one-time $500 cash bonus once you spend $4,500 on purchases within the first 3 months from account opening. (click link!) They also have travel cards as well!