You join the firms out of school, they will ask you to register with ICAEW/ACCA and study to become a chartered accountant (CPA in the US), the firm will provide you with books, exam fees and tuition fees while you earn on the job. After three years while your peers finishing up at university you will have a solid work history with great qualifications with no debt. You can even get a degree if you join ACCA for just ₤200 for submitting a thesis and no additional exams.
While in the US, to become a CPA, you would need masters level education in most cases to even appear for the CPA exams. UK and almost all commonwealth countries have programs and institutes that offer professional qualification opportunities with even more prestige than the average university route. Accountancy is one of the few fields where one can get-qualified-on-job in the Anglosphere (US, Canada excluded).
ICAEW : http://careers.icaew.com/school-students-leavers
ACCA : http://www.accaglobal.com/uk/en/qualifications/accountancy-c...
ACCA + B.Sc (Hons.) :http://www.accaglobal.com/gb/en/help/oxford-brookes.html