I completely forgot that my CC payment was due in a few days. If I make a phone payment on my capital one card today, will the $15 phone fee be immediately deducted from the credit card, or will it post on the closing date along with finance charges?

I currently don't have enough on the card to cover the fee, and won't be able to pay the card off until next month. However, I plan to make the minimum payment, along with the additional $15 fee tonight, and I didn't want to acquire an over the limit fee.

p.s. I'm not able to make a free online payment at this time. Thanks