You can't charge your MasterCard bill on your Visa card, but you may be able to use the line of credit you have available in one account to pay obligations incurred on another. Be wary of taking this approach, however. The costs of paying off debt by incurring more debt only makes your balances worse.
The easiest way to pay one credit card bill with another card is via a balance transfer. In doing so, you're taking the debt from one card and applying it to another. That counts as a payment for the credit card issuer's purposes, so you won't incur late fees or derogatory entries on your credit report. Balance transfers can be conducted by mail, over the phone or online by most issuers.
Online Bill Payment
The most convenient way to a conduct a balance transfer is online, and it also can be the quickest way of getting your account credited. If you have a convenience check, pay your bill online using that as you would a personal check. The convenience check will have a nine-digit number corresponding to the issuing bank's routing number, as well as a longer account number. The latter may not be the same as your credit card number. If you don't have a convenience check, you still may be able to conduct the transfer online. Log onto the account of the credit card you want to transfer the money to, and click on the link that allows you to transfer a balance.
Balance transfers generally come at a price. You'll pay somewhere around 2 to 4 percent of the amount transferred as a fee, and you'll also pay a higher interest rate than you would on an ordinary purchase. As a result, your overall debt likely will rise. You can mitigate this by searching for cards with promotional offers that provide low balance transfer rates for a prescribed period. However, you generally need to have a good credit score to be offered these promotions, so if you're maxing out on your cards you'll have to search harder than others to find one of these deals.
You also can pay a credit card by taking a cash advance from another card. As long as you have your PIN and an available line of credit to access, you can take out cash at either an ATM or with a bank teller. Use that cash to pay the other credit card bill. However, interest on cash advances generally has a higher rate than on purchases, and there isn't any grace period. That means you'll start accruing interest charges right away. Most cards let you use only a percentage of your credit line for cash advances, so you'll need to check that you have enough before going down this path.