In what could be considered the latest fallout from the subprime mortgage crunch, the Financial Times reports that credit card companies were forced to write off 4.58% of payments as uncollectible during the first half of 2007, an increase of 30% over the amount during the same period of 2006. Citing data from Moody’s, late payments also rose, while the quarterly payment rate fell for the first time in more than four years.

Analysts at Moody’s suggest that as interest rates have crept up and the housing market has slowed down, consumers are less likely to pull equity out of their homes to pay off their credit card debt. However, Moody’s also told the F.T. that it is unclear if the people defaulting on credit card payments are the same people defaulting on subprime mortgages, in part because underwriting standards have generally been more strict for credit cards than mortgages.

There already has been some reaction among credit card issuers. The Wall Street Journal reported last week that USAA has tightened their underwriting standards and raised their score cutoffs slightly on their auto loans, credit cards and personal loans. USAA is also being less generous with its automatic credit line increases. According to the WSJ, lenders can afford to be more selective and to charge more for their services because more consumers — increasingly locked out of home-equity loans and lines of credit — are using their credit cards more. Recently, Bank of America, Capital One, and Discover have all raised rates and fees for some credit card customers.