Do they open packages in customs?

What do they do with packages at customs?

• I sent out a package from the US to the UK last Thursday. I was notified that it had made its way out of US customs immediately, and was on its way to its destination that Friday. But, what happens to packages at customs in the UK? I'm a little worried because when I was at the post office, they had me fill out a customs form of what was in it. There were only 4 spaces where I could write down my stuff, and I wasn't able to write down everything which was in the package. Apparently, this was fine with US customs, but will it be fine entering the UK? The people at the post office were very unhelpful. This is the first thing I've ever mailed out on my own, and they literally acted as though I was supposed to know what was going on. They never explained how long it would take, if I did okay on the customs form, etc. So... Could anyone with experience let me know if my package should be okay?

• Answer:

  As long as there was nothing illegal in the package then it should be fine. How long it will take to arrive depends entirely on whether you sent it airmail or surface mail. Airmail could take a week to ten days but surface mail could take up to six weeks to arrive...