<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by LHR Tim:
However for some countries (such as the UK) it only has to be valid for the duration of your visit in the US. If, for instance, you had two months remaining on your UK passport, you would be admitted for only two months instead of three. (OK, OT, but what the heck!)</font>
(Slightly off topic as this is for UK passport holders)
Indeed - the London US Embassy website states that under the Visa Waiver Program the requirement for 6 months validity has been waived. (!)
It's a bit comfusing as the US Immigration site (as opposed to the Embassy) clearly states you need 6 months validity from the day you intend leaving the US. (Potentially 9 months).
Given the number of changes to policy that have frequently made due to hightened levels of alert (etc etc) I would suggest anyone who is marginal (i.e. 10months or less on their passport) gets a new one sooner rather than later as these requirements could quite easly change without any great fanfare leaving you high and dry. UK Passport Office (UKPO) will give you 6 months 'credit' on your new passport anyway.
Also (and this will probaby change) if you don't renew before October and have an older passport there are suggestion you may need a visa in the future. (There's been a fair bit of news about this and to be honest I dont know the full story - just thought I'd add it as a thing to keep an eye on)
Getting a new passport in the UK these days is easier however be aware you can no longer just turn up. Check out UKPO site for full details. I did the fast track service recently in Glasgow and found it very efficient - I was in the office for all of 5 mins whilst they checked my forms, passport arrived a few days later.