I got this question recently:
“I’m trying to seek advice on registering my screenplay. I live in Australia and have just completed a first draft. The story is based in the US and will be targeted at the US market. I believe WGA registration is okay for non US citizens but what about the US Copyright Office? Is that valid for non US citizens as well?”
I’m really not an expert in this area so you might want to do your own research. In general I think both the WGA and the US Copyright office will work for you even though you don’t live in the U.S. In your case I would use both. Use the WGA online registration form. That way you’ll immediately have a WGA number and won’t have to wait around for the US Copyright office to get back to you. In my experience the US Copyright office has taken 6 months or more to get back to me – and I live in the US – so it might be a long while before you hear anything out of them.
Having a copyright or WGA registration number for your screenplay is only a formal way of establishing when you completed your script. Even without it people are still not allowed to steal your stories and ideas.
As with all legal matters, I highly encourage you to consult with an entertainment lawyer if you have any legal questions.