is my friend over stayer?

[touchwood]

Hi
One of my friends in Pakistan was having five years multiple entry visit visa. He came to UK last year and stayed here about eight months continuously without informing honme office and went back to Pakistan. Nobody at airport questioned him about his over stay while he was going back. Now he is willing to visit the UK again. His visa is valid for four more years. I want to know is he an overstayer? If yes, what can happen to him if he travels and how can he visit the UK again?
Many thanks

[Mr Rusty]

The maximum a visitor can stay at any one time is 6 months, so if your friend stayed 8 months he was an overstayer. He was lucky not to have been questioned when he was leaving the UK, as some people in such circumstances have been served with a notice as an overstayer.
He may be ok when he comes back, but if the IO chooses to examine the stamps in his passport and see that he didn't re-enter Pakistan for eight months, he will have to explain what he was doing and why. I would advise him not to lie about this, or to attempt to alter the stamps in his passport. If he does either of these things his visa will be cancelled, he will be refused entry and he will be banned from the UK for a long time.
There is at present no legal bar to him visiting the UK again, but the guidance to Immigration Officers says that they need to look closely at passengers who appear to be spending more than 6 months in any 12-month period in the UK.

[vinny]

He may be refused entry under 320(5) or 320(7B) (if he has been away from the UK for less than one year).