say for my card the statement is cut by the 10th of every month and the due date is on the 20th (just for instance). So, the best payment policy would be to pay the whole balance off before the 10th? then the statement balance would be 0?
(I definitely always pay off before the due date, but it is not enough)
if not then when would be the best time to pay the card off in the above scenario?
You wouldn't find a senario with those dates in real life, but we'll work with them here as an exercise. The difference between the statement and due dates are known as the grace period and in real life is usually somewhere around 23-25 days.
Your statement (which tells you how much you owe) is dated on the 10th, and it specifies the 20th as the due date. That means that the entire balance as reported on the 10th has to be received and processed by the card issuer by the 20th for the account to report a $0 balance. Mailing a check on the 20th, or pushing a payment from your bank on the 20th, won't count.
@coldfusion Are you sure this is right? If OP pays after statement (The 10th in their example), the balance won't be zero. Statement balance is what reports, isn't it?
You need a starting point of reference, and the statement is the reconciliation notice from the creditor that specifies how much is owed.
Payment in full is made and credited to the account by the due date. Following statement reflects a $0 balance and reports as such.
In the real world you also have to contend with ongoing active use and the related cutoff dates by which charges can be posted and show up on the upcoming statement, but that's beyond what was specifically asked here.