Consumers’ progress during the economic downturn in paying down their credit card debt appears to be in danger after major card companies reported that late payments spiked in September.

Five of the nation’s top six credit card issuers said Monday that late payments edged up during the month, the first time since February 2009 that payments late by at least 30 days have risen.  The increases were less than 1 percent, except at CapitalOne, which saw delinquencies rise to 3.65 percent of balances.

Last week, the Federal Reserve said that its member banks reported a 3.4 percent annualized decline in credit card balances in August. Total revolving credit outstanding fell to $790 billion in the month, from a peak of $972 billion in September 2008.

At American Express Co., delinquencies accounted for 1.5 percent of balances, up from 1.4 percent the month before. That’s the lowest delinquency rate in the industry. Discover Financial Services’ rate, which was 2.5 percent, also rose just one-tenth of a percentage point, while Chase, the nation’s largest card company by spending volume, posted a rate of 2.53 percent, up from 2.48 percent, the Associated Press reported.

One reason card rates remain stubbornly high is the rate at which banks get stiffed by cardholders.  Industry-wide, the default, or charge-off, rate, hit 10.96 percent of balances in 2010's second quarter and has since declined to 5.6 percent in this year’s second quarter.

The average credit card debt per household is $15,799 and the average interest rate on cards is 13 percent.  At $150 a month, that debt will never be paid off. At $266 a month, it will take eight years and the interest paid will be $9,693.  The Federal Reserve has a handy calculator where you can figure out your credit card payoff using different assumptions.

(An earlier version of this story used incorrect payoff figures in the final paragraph.)