This part isn't strictly true as some credit card companies allow you to transfer credit to your bank account. But they usually charge a higher interest rate or this is seen as a cash withdraw on the credit card. It's not in your best interest to do this. In the case of credit card transfers. Once you've moved your balance to the new card, (You usually to this to benefit from a lower interest rate) Do not use that new card to buy anything until you have paid off the balance on that card. If you start spending on that card the interest is calculated on the full balance of the card and not on what you just spent on the card recently. In short, what ever you buy on a credit card make sure you can pay it off at the end of the month. This way your charged nothing.