I always thought you could be picked up and deported if you overstayed the amount of time stamped in your visa. Am I hearing you right? Just gotta make sure.
First things first: To overstay one's visa is a criminal act. It doesn't matter if one was intending to settle here or not, it's a criminal act any which way you roll it.
BUT that was not what I was referring to. I was referring to the "spent leave" rule, the 6 months out of 12 months thingie that is vectored all over the internet as sort of immutable law - which it is *NOT*. You can see, even on this board, people babbling on about it who actually have no idea what they are talking about. They are just vectoring stuff from "other" forums.
So let's have a look at the Entry Clearance Manual again (Chapter 2, Annex A):
..There is no restriction on the number of visits a person may make to the United Kingdom nor any requirement that a specified time must elapse between successive visits. The fact that a person has made a series of visits with only brief intervals between them would not, in the absence of any other relevant factors, constitute sufficient ground for refusal... That looks pretty clear. And then it goes on to say:
"...It is reasonable, however, for the immigration officer to consider the stated purpose of the visit in the light of the length of time that has elapsed since previous visits. A visitor should not, for example, normally spend more than 6 out of any 12 months in this country (but see Section 3 of this chapter in the case of visitors for private medical treatment)..." The key words here are "reasonable", "should not", and "normally". It's a constructive rule, not a policy. If somebody has a good reason to be here, then they simply need to convince the IO of it and that's that.
I recently answered an enquiry from an American woman who came in on a visitor's visa last September to stay with her bf. They went to Scandinavia for Christmas and re-entered in January where she got a new standard 6 months visitor visa. So she's good until 7 July, and that makes 10 months! All legit. And yes, poise, aplomb, confidence had much to do with it. It all depends upon what the IO is thinking and the whether or not you have a good reason to be in the UK.
If the IO thinks you are dodgy, or even *worse* suspects that you have a typically American cavalier attitude towards UK immigration law, you will *NOT* get in if he can nail you on "spent leave". It's constructive.
Hope that clarifies.