I personally called the home office to ask this question - and was told six months. However, the answer was "six months within any twelve month period" - so it seems it would be difficult to leave and then return for another six months.

This was for any U.S. citizen.

 

I suppose this depends on who you get as a "passport control" worker. I've travelled into the UK 6 months at a time with only 3 weeks between vistis for the past almost 3 years (this was to work up to a necessary 2 years cohabitation requirement) and I got through fine. Well, up until the last time, when the bloke thought I was "living" here - LOL as if! yeah ok, but not the point! =o)

It's like, when you apply for a Visa, or any permit with the Home Office, it all depends on who you get, consider it a "lottery" if you will...just always hope you don't get someone who feels like the world is their enemy that day!

My opinion...

ok, take care =o)