In the UK you do not need any formal qualifications to get into teaching.
School heads have long had the power to recruit who they want (all stemmed from the shortage of Math's teachers).
It's not widely made known or admitted to.
Once in post they send you off for part time Teacher training - which satifies all parties. For FE and HE, if it is a shortage area, the story is the same.
Of course the Police backgroud checks will apply in all cases.
If you have a reasonable grasp of GCSE math's and are prepared to move anywhere you will be on 25k within 2 months.