The best way to protect yourself from overnight hikes in your credit card’s interest rate is to, first and foremost, avoid credit cards with the universal default clause. Not all of credit cards practice this clause, only about 40%, so be sure to look carefully into your credit card’s fine lines and policies.

If your credit card does practice the universal default clause, be sure to check into your current credit card policies. If you are unsure of anything in relation to the policies of your card(s), do not hesitate to contact your credit card issuer to verify the facts. If you are currently using a credit card with the clause, consider transferring your balance of that card to one of your cards that doesn't practice the clause. However, do not rush to cancel the card altogether, because it could have a negative effect on your credit score.

The easiest way to avoid higher interest rates with a current universal default clause credit card is to simply pay your bills on time – all of your bills (even those not part of your credit card).  If you are struggling to pay your bills on time, such as car loan and mortgage payments, contact your lender to try to create a manageable payment plan.
 
Currently, there are amendments to the Truth in Lending Act that, if passed, would prohibit many unfair practices within the credit card industry, including the universal default clause. Until there is more justice among the practices of credit card companies, it is up to you to maintain a good record with your bills by paying them on time and understanding your credit cards and credit score.