You may be able to use your credit card on the same day you transfer the balance. This is known as a 'same day balance transfer'. Some providers allow a same day balance transfer if they get the request before 5pm. But this depends on when your old provider processes the payment. Other providers will process your transfer by the next working day. To avoid unnecessary charges or late fees, you need to keep up your repayments on your old card until the balance in transferred.