How to combine shipping

[ericlovescameras]

A buyer bought a buy it now item and then 15 minutes later another. My listings descriptions say I combine shipping and I check that box when making a listing. But the buyer paid separate shipping. Any official way to combine? Or is the only way to refund on the side? 

Thanks 

[sam9876]

 Put both items in one box and ship it.

[ericlovescameras]

Oh, never mind. Separate addresses. Someone is Xmas shopping. Still curious for the future. How does combined shipping actually work? I know refunds outside of eBay put me at risk so hows it work in the system?

[ericlovescameras]

Ha, I mean combine shipping cost. Would be nice if eBay knows one label is for multiple items as well.