Qualified Teacher Status (QTS) is the recognised teaching qualification for state schools in England. You don't always need it before applying for sponsorship, but you must achieve it within a set period after starting work.
International QTS recognition
Teachers qualified in Australia, Canada, New Zealand, Singapore, the USA, EEA countries, Switzerland, Ukraine, Hong Kong and several others can apply for QTS recognition without further training. Apply via the Teaching Regulation Agency (TRA).
iQTS (international QTS)
A one-year training programme delivered overseas by accredited UK providers, leading directly to QTS. Costs are similar to a UK PGCE.
Assessment Only route
If you're already an experienced teacher with no recognised QTS-equivalent qualification, you can be assessed against the Teachers' Standards once in post in England, typically over a 3-month period.