Finance Charge Question

wruwtrix

I recently got my first credit card and now I have a question about how my finance charges are assessed.

The following is copied from my credit card terms and conditions:

The grace period for purchases is at least 20 days. Therefore, to avoid periodic finance charges on purchases (excluding balance transfers) that appear on this statement, you must have paid the New Balance on the last statement by that statement's payment due date and also pay the New Balance on this statement by this statement's payment due date.

In June, I only paid around 80% of my (425.36) balance.
In July, I paid 100% of my (332.92) balance by the due date.
In August, I was charged a finance charge on a portion (exactly 860) of my purchases (totaling 1111.51). I can't figure out how they came up with the amount that was applicable to the finance charge.

Does my T&C require me to have paid the previous two months in full to avoid finance charges? What purchases are applicable to a finance charge if I've paid the previous month in full before the due date?

Thanks for your help!

CLAPTON

Essentially you need to pay the total amount of the balance for two consecutive months to avoid interest charges.

Look at t like this.
From the time you buy something on your card the interest starts clocking up on a daily basis.
If and only if you pay the FULL amount they will waiver the interest and you get the advertised 'free' period.
But you didnot do this so the interest was worked out from the date of purchase until you paid it back.
Some was paid back on first bill (80% but interest was accrued that would be charged on the NEXT statement) some was paid at after the next statement (but was still clocking up interest ) so there was still some interest to be paid on the third statement.