I won an iPad 2 and for me to get it to the UK, I've been told to send them the W-8BEN form. I sent it to them first excluding the the U.S. Taxpayer identification number but, later received an email saying:

"we noticed that there was no identification number provided. We request that you please resubmit the W8 completed correctly"

I'm now confused on what to do. What should I put? What box should I tick (SSN or ITIN / EIN)?

Or maybe I'm thinking of the wrong box would the "Foreign tax identifying number" be relevant here?