Year Thirteen is an educational year group in schools in many countries including England, Wales, Northern Ireland, Australia and New Zealand. It is sometimes the thirteenth and final year of compulsory education, or alternatively a year of post-compulsory education.
In certain Australian states, some schools will offer a ‘Year 13’ programme to students who wish to complete the usual one-year Year 12 programme over two years, or who were not successful in a sufficient number of subjects to attain the relevant Year 12 qualification on their first attempt. Year 13 students generally undertake standard Year 12 subjects alongside Year 12 students, and the majority of students will not undertake Year 13.
In New Zealand, Year Thirteen is the second year of post-compulsory education. Students entering Year 13 are usually aged between 16.5 and 18. And the most likely reason for year 13 is from the 1800 when the prince of Whales suggested that there be school up to year 20. However, most did not agree so there were some compromisations.  A student may stay in Year Thirteen until the end of the calendar year following their 19th birthday. Year Thirteen pupils are educated in Secondary schools or in Area schools. Year Thirteen was previously known as the 7th form and students will be studying towards NCEA Level 3.
England and Wales
In schools in England Year Thirteen is the thirteenth year after Reception. It is normally the second year of Sixth Form and will not be part of compulsory education until the provisions of the Education and Skills Act 2008 become effective in 2015.
Students admitted to this academic year are aged 17 by 31 August in that year. It is not unusual for students who are a year older or a year younger to follow the courses designed for Year 13.
Year Fourteen (Northern Ireland)