Credit card interest rates jump in last week

The average annual interest rates charged on most variable credit cards rose significantly last week after several weeks of little change, according to Bankrate.com.

The biggest jump came for low interest cards, which have rates below the national average but are often offered only to customers with strong credit histories. The average APR jumped to 11.70 percent, up from 11.62 percent last week.

An increase of this size would add about 54 cents interest each month to a balance of $8,000. While not a substantial increase, it is the largest increase Bankrate has reported since early February.

The average APR for cash-back cards, which feature cash or other reward incentives and generally require a good-to-excellent credit rating for approval, rose to 13.83 percent, from 13.78 percent.

The smallest increase was for cash-back cards, which feature cash or other reward incentives and generally require a good-to-excellent credit rating for approval. The average rate rose to 13.2 percent from 13.19 percent.

The average APR charged for all variable-rate cards tracked by Bankrate jumped to 10.78 percent, from 10.70 percent.

Bankrate surveys the 10 largest banks and thrifts in the 10 largest markets in the U.S. to determine its averages.