common scenario.... family emigrates to uk, gets residency one way or another, placed in council housing, awarded benefits, parents then return to home country, leaving unsupervised child alone in council house, living on benefits.
I know of two cases where children left like this have locked themselves out, and moved in to sleep on someones floor, leaving the home empty for months.
Or "own children" arriving alone, applying for asylum, maybe turned down, but allowed to remain until the age of 18, which can backfire, as I have known several students deported mid A levels.
Or families arriving with holiday visas, then enrolling children at school while they are here, maybe get away with it for a few years, maybe forever. ( The last family that I am aware of that did this was deported within a month of enrolling)
Last year at sixth form enrollment, spoke to a distraught father of a 19 year old son, who couldn't believe his son was being turned away because he was too old. He said he had come to uk specifically to get his son an education.
I've lost count of the number of times the same woman has turned up at consecutive parent teacher meetings being the "mother" of 6 or more children, all in the same school year, if you question them, they admit they are "aunties" , adults overseeing many many different children, who have been left in their care unofficially by overseas parents.
These are the ones that stand out. There are the others who still remain together as a family who may quietly admit they have come to the uk for the free education, or who you may suspect have, but don't say so.
Like I said, I have known hundreds. literally hundreds.
I've never reported any, as it isn't my job to act as border control. Apart from anything else, such children have done nothing wrong themselves, it is their parents who have, but it is the children who are punished if caught. i had one tutee recently who was caught and deported at 18, but her parents wouldn't take her back, as she hadn't got the qualifications they hoped for,