As far as I know, and I am the signposter not the advisor, that depends on a wide range of issues like country of origin, reason for lack of visa. But yes, I think there is always a time penalty.
At risk of being called all sorts of names, we have a 'yo-yo' family. They come specifically to steal and beg. Individual members of the family have taken the resettlement money already but keep coming back to carry on to carry on as before. We can't tell them the risk isn't worth it because, to date, they have made an absolute fortune doing it - a UK size fortune at that! So they will keep on bringing the youngest members of the family over and will take any penalty as an occupational hazard.
They aren't the norm, in 20 years I've never met anyone else like them, but I suspect they are the kind of people most racist's think of when they imagine foreign benefit cheats etc.