How do I enter my OUAC number on the application form?

Entering the OUAC number on your application form is optional. If you choose to include the number, it must be in the format of an 11-digit number without hyphens. 

Remove the hyphen from your number, and if your number is only 10-digits long, add a 0 (zero) at the end of it (e.g., 20XX9911990).

This information on the Ontario Universities' Application Centre website discusses the OUAC number: