Want to pay the charges on your postpay threshold account? You don't have to wait until your next billing cycle.
To see the list of currencies and payment methods acccepted for your billing country/region, see Choosing a payment method for Microsoft Advertising. And, if you want to review whether a prepay account or a postpay threshold account works best for your needs, see What are my billing options? Pay now or pay later.
You cannot pay only a portion of your account balance. When you make a payment, your entire account balance is charged to your primary payment method.