My understanding is that the Chase Slate is designed to be a card for lower-income spenders like students, so it shouldn't be too hard to get. So applying for it and transferring the BoA balance to it when that card's introductory 0% APR is about to expire would be a good way for you son to pay down his debt without too much pain. (Although in this case a little pain is a good thing! Nothing like a bit of pain to make us not repeat a mistake, and at least your son's learned the lesson early before he had the time or the credit limit to get in serious trouble.)

OP, take a lesson from this. It is REALLY EASY to get in over your head with credit card debt, and the card companies will entice you to do so! NEVER EVER EVER carry a balance on your credit card. It's a bad habit that's easy to get into, and if you do that with the travel rewards cards, their high interest rate will eat you alive. Pick one nice card to start with ( recommend a cash back no annual fee card as a first card), and stick with just that card for a year or so before applying for anything else. Learn to discipline your spending before you have a high credit line where you could get into serious debt trouble. About 2/3s of American families will be debt slaves all their lives because they carry balances on their credit cards which they wil never succeed in paying off. Don't join their ranks!