Maybe more importantly, your score probably won't take a hit. The business card doesn't report on your personal credit report. If it reports, it reports on your business credit report, which is completely different.

But do charge cards really report out on your credit reports at all? I had heard that they didn't, since they're charge, not credit. I'm not somewhere where I can verify right now, but it may be worth double checking. It's very possible that they're not currently reporting at all, so closing them would have no effect whatsoever.