I want to travel shortly to the US on a UK passport with visa waiver which would expire about 5 months after the end of my trip. The INS website says it needs to be valid for 6 months after the end of the trip but the much more detailed US embassy (in London) site says that there is a reciprocal arrangement between the US and many other countries (inc. the UK) waiving this requirement. (It says 90 days are required, but if the passport is valid less than 90 days, the visa waiver simply expires at the same time as the passport.)

I'm inclined to believe the embassy information over that of the INS simply because it is so much more detailed and because it would be a real pain to renew my passport before travelling. Nevertheless I am disconcerted by the apparent contradiction. And there isn't anyone obvious to ask about this! Except you guys of course...