We looked into this few years ago.
There’s a great College Fair in London which is worth going to to speak to people and get loads of prospectuses etc (not sure how this will work in the age of Covid)
SAT preparation is key - especially if candidate has dropped maths after GCSE or has specialised in science and dropped essay subjects. There’s a particular technique. DS did a course in London in the summer after GCSE (£500) and the mock test scores informed where we looked (each College will say the score they will expect for entrance).
The school/college is much more involved in the application process than UCAS- they have to do various paperworj in support of the application. You need to find a staff member familiar with the process or willing to take time to learn.
Offers are made before A level exams are taken. Would your child be motivated to carry in and take exams that have no impact?
We went to visit the College we liked the look of. They love overseas students as they pay big bucks!! It would have been around $50,000 all in. We were told that A level study is at the same level as first year College courses. It was implied that as he was predicted high A level headed they would accept him regardless of SAT score. See above re big bucks!!!
Student life is very different. First you are likely to have to share a bedroom with at least one other person. There’s no real culture of moving off campus after the first year, I got more of a boarding school vibe. Kids don’t cook for themselves etc like they do in UK.
You have to study a variety of subjects for at least 2 years before you specialise. For us this was the main attraction of the US system. But most professions require a post grad degree.
We didn’t look seriously into visa issues but I can’t see the US system being more generous for foreign graduates than we are - the dream of being able to stay on and live there may be just that. It’s not automatic.
For a variety of reasons my DS decided against it.