So I know when you use your student card to buy books/other from titles it goes on your student account with McMaster. But I'm a little confused as to when it has to be paid off. 
here: 
http://www.bookstore.mcmaste  r.ca/i...-accounts.html
it says that "The last day to charge on Undergrad Student Charge  Accounts is 
March 31, 2011. Payment is due by 
April 15, 2011."
and also says "...will have to be paid back before you receive your marks or  register for the next semester."
So if we use it during first semester do we have to pay it off before 2nd semester or can we pay it off before the end of the year? 
Any help from anyone who's familiar with this is appreciated.