Once you’ve completed your balance transfer, you may decide to close your old credit card. However, that’s not always the right choice. Closing an old credit card, even if you don’t plan to use it again, can negatively affect your credit score. However, if you’re worried you’ll overspend on the card again, it may be in your best interest to close it despite the short-term credit impact. After all, racking up more credit card debt would have an even worse impact on your credit score.