If you are shipping Ball Pythons! No problem as they are the only legal type of snakes that can be shipped to PR. Only can ship Fed Ex, or Delta Dash or similar way.
You have to make sure there is a Health Certificate in the in the box along with an invoice. Now I know of people that ship other ways and they are not right. It cost a bit more to ship to PR but no different than shipping in the states. Just have to make sure the documents are in order.
When they are shipped the receiver has to notify the PR Natural Resources (Game Wardens) and they will verify the contents of the box and then release the snake to the new owner.
I hope this helps you out.
Tom
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Thomas Sierra