Sending to UK makes me nervous. I've lost a couple of packages going there. They need to get their act together there. Even my UK customers tell me their own Royal mail sucks donkey ass.
Given where morale is headed in the USPS system, I can only hope that the postal police will keep that kind of behavior in check in the US.
One of my funnier experiences with the (generally awesome) German postal system was sending a gift package to my god-daughter over there... except it didn't arrive... instead, the mother got a notice to pay up... long story short, the Droid at the customs hall took a look at the contents listed on the customs form, noted "gift", read it in German (in which case you're shipping 'poison') even though the package came from a English-speaking country and items shipped internationally are always declared in English, and decided that a duty applied. A terse letter from the mother regarding the English-reading skills of the droid in question unlodged the package without the need for duty payments. Naturally, without comment.
...kudzu in the SE of the USA, the cane toad in Australia...