How can a US teacher get a job in a British Public School?
What do you mean by Public School? Do you mean a publicly-funded school (i.e. Maintained, Academy or Free School), or an Independent School?
Whichever you mean, you have a number of administrative hurdles to jump over.
Are you a Citizen of an EU Country or other person with the right to live and work in the UK according to Asylum and Immigration Act 1996, the Asylum and Immigration Act 2004, Immigration Order 2004, Immigration Order 2007, Immigration Order 2014, Immigration, Asylum and Nationality Act 2006 and all other relevant legislation?
You should check with the British Embassy if you are unsure - I cannot advise you.
Qualification to teach in a maintained school in England and Wales is governed by law. You will need to acquire Qualified Teacher Status, and so you need to investigate this. The GOOD news here is that US qualifications are processed very easily. New regulations that came in a couple of years ago provide this.
There are schools where you do not actually legally need QTS - Academies, Free schools and Independent schools - although most of them will nonetheless require it of their applicants as it is a sign of the fourth point below probably, although not certainly, being covered.
You need familiarity with the UK schools system. This is often the very first point on the person specification: Understanding and experience of the National Curriculum. And this will be your big problem, to be honest. Schools nowadays are very strictly regulated, and are subject to almost-no-notice inspections.
If a teacher isn't up to scratch, hasn't understood what to do, how to do it, what data they should be using, how to ensure inclusion of all pupils, what format of lessons, then it can be very serious for a school and for a Head. Which brings me to point five . . .
We are told that there is no crisis in teaching, but we know that in some areas for some teaching subjects there is a dire shortage of teachers. Maths, Physics, English, Chemistry hoping to work in the East Midlands or the London area and SE? Primary teacher ditto? Come on in!
However there is also in some parts of the country an over-supply of teachers; this is mainly Primary in the SW and NE. As a result, some Primary teachers are unemployed, and there is a falling demand for P.E. Art, Music and even History in some Secondary schools, where Headteachers are having to make staff redundant to cope with falling budgets.
Any surplus of teachers, where it exists, is predicted to melt away over the net few years, as the demographic bulge currently arriving in Secondary moves up, and schools feel the double-whammy effect of lower numbers of new teachers starting their career being out-numbered by teachers giving up their career well before the retirement age. However in many areas currently there are still healthy numbers applying for many posts, so Heads have a good choice of candidates.
In these circumstances, you will understand that a Headteacher will prefer to employ someone who is UK-trained and UK-experienced, of whom there are still good numbers at present, instead of running a risk.
Because you would be a risk, I’m afraid.
The possibility of the Inspectors arriving at a day's notice and finding someone (i.e. possibly you) not au fait with all aspects of the curriculum and student support would be a very large risk for Headteachers. You would be advised therefore to try your hand at Supply Teaching first, to get yourself familiarised with all aspects of the life of a school, including GCSE and A-level.
Your best chance of permanent employment might be to contact the American Schools in London, where your experience will be an advantage, not a disadvantage.
The American School in London
ACS International Schools Home page
TASIS The American School in England, London, UK
Hope that's helpful.