Yes, you can ship to Puerto Rico just the same way you would ship to any other U.S. state. The buyer recommended USPS because UPS and FedEx considers PR as international and you would have to fill out an international form and maybe pay more than it is worth. I would ship USPS and it will even cost the same as if you would be shipping anywhere else in the US.

Puerto Rico *IS* part of the United States. You just use the USPS as usual. Their zip code is the equivalent of shipping to Hawaii.

What NA said. And BTW, you CANNOT ask a buyer to pay additional shipping after the auction has closed. It is YOUR responsibility to block bidders who live outside the area to which you are willing to ship.

I just started selling on eBay last month, and until now, I've only been shipping within the US. Recently, I got an order from Puerto Rico, and I haven't shipped overseas before. The buyer says he doesn't mind paying additional shipping fees, and to use USPS.

I'm not sure how it would work for my item, but the dimensions are 6.9 x 6.9 x 6.9 inches all around. I checked their website, and I didn't see anything that could fit that. Do I have to find another shipper?

If it matters, it's about 2.2 pounds. A light package going to 00917 from Georgia.