How to pay 0% interest on credit card debt?

Flipper, don't let my son end up making me broke this way<br><br>Last year I gave my son a credit card with $5k credit limit so he could help pay for some of the renovations he was doing on his first house. The story starts because of where he spent $5k first. <br><br>He used $5k of the $5k credit limit at Home Depot. On a Sunday. When credit car companies don't seem to process payments. By Tuesday afternoon my credit card had been turned off because the payment was 5 days late. I tried to call the credit card company and explain that this usually is an automatic payment and that I had paid every bill on time. "Sorry", the lady at the credit card company said. You can still make the payments, in fact, we are going to let you keep this payment amount. But your interest on this debt will be 30.9%. <br><br>So the credit card company fined me 30.9% interest to the tune of $1500 a year (I wasn't going to try to pay off the $5k in a month, but I planned on paying it off in about a year). I was not very happy about this. <br><br>So I paid off the $5k at a 0% interest. <br><br>How did I do this? I used a 0% interest on Citibank Citi Premier card of $30k credit limit to pay off the $5k that would be 30.9%. The only catch is that Citibank charges you 3% for the transfer of funds. So in essence it cost me $150 to transfer the money. I saved $1350 by doing this. <br><br>So I now have a $5k 0% interest payment on my Citibank card that I must pay (which I would have to pay anyway). I just have to pay this $5k off in the next 21 months per the Citibank card rules for 0% interest. I also have to pay Citibank $150 per year on a $30k card to keep it. So $5k / 21 months is about $240 a month for the next 21 months to pay off the amount I took out. <br><br>I will still have to pay Citibank $150 per year to keep the credit card with the 0% interest, but I will also still save $1350 by doing this, and I will have 0% interest on a $30k credit card for 21 months. <br><br>Like I said. I was going to pay off the $5k across the 12 month period anyway. But I saved $1350 doing it this way.