If you forgot to claim your tuition, education, and textbook amounts in a prior year, you CAN'T enter the tuition on this year’s return. You must amend the prior year return, claim the credit in that year, and then calculate any unused amounts that you’re allowed to claim this year. This might involve changing tax returns for several years.
For example, let’s say you’re working on your 2016 tax return and you forgot to claim a T2202A from 2015. You must:
1. Start by amending your 2015 return to include both the federal and state tuition, education, and textbook amounts.
2. Determine the unused federal and state amounts available to carry forward from 2015.
3. Amend your 2015 return to include the unused tuition amounts.
4. Determine the unused federal and state amounts available to carry forward from 2016.