It should really be called the 16 month non-Induction, short-term teaching limit. The 16 months count down from the first day of qualified non-Induction teaching and the clock doesn't stopp counting down during periods of unemployment or school holiday weeks. It's actually possible to do one day of supply, get no more bookings and run out of the opportunity to take non-Induction work 16 months later. If you are about to run out of the 16 month 'window' and haven't yet started or completed Induction, you can apply to each LA where you might want to get short-term teaching . You need to prove to them thatnot yet having completed Induction is not your fault. The LAs can award you up to another 12 months to take short-term teaching in their schools or they can reject you application. You can take as long as you like to complete Induction, subject to the short-term teaching limits. If you take 10 years, most of that time will see you out of LA 5-16 schools. You are not limited at all for teching in Post 16 or in the private sector.