U.S. credit card issuers increased cardholders' annual percentage interest rates by 20% between January and July of this year, while maximum balance-transfer fees increased by 34% during that period, according to a new study from BillShrink Inc., which operates a Web site that claims to provide consumers with free, unbiased credit card recommendations. The Redwood City, Calif.-based firm says it based its analysis on a review of the interest rates and balance-transfer fees of 150 card programs. The company studied long-term rates and fees, excluding card programs' introductory and promotional rates and fees. Issuers on average increased their annual percentage rates by 20%, while they raised the average maximum amount on balance-transfer fees from $94 in January to a maximum average of $126 in July, the company says. The average credit card annual fee remained unchanged through July at $25 per year, while the average late- and over-the-credit-limit fee also remained stable at $28. "As card issuers react to the changing economy and new credit card laws, we may see issuers discontinuing some existing card programs while offering to switch customers to new card programs carrying different fees," Samir Kothari, a vice president at BillShrink, tells CardLine. BillShrink also is tracking on its Web site which issuers have complied with various provisions of the Credit Card Accountability, Responsibility and Disclosure Act, which President Obama signed into law last May. Although most provisions of the law take effect next February, some new rules take effect this week. Beginning tomorrow, issuers must provide customers with written notice 45 days in advance of any significant change in account terms, and they must mail credit card statements at least 21 days before the payment due date instead of the 14 days previously required.