NEW YORK — Americans are starting to get their household finances in order.

In an encouraging round of earnings reports, major banks say fewer mortgages are going bad, credit card defaults are down and more people are paying the bills on time.

One of the nation’s largest consumer lenders, Wells Fargo, said Wednesday that 29 percent fewer loans went bad in the last three months of 2010 than the year before. And late payments on loans considered likely to default declined for the first time since 2008.

Late payments on credit cards issued by Bank of America, JPMorgan Chase and Citigroup also improved at a record pace at the end of last year, according to an analysis by Barclays Capital.

The reports are a sign that Americans are feeling more comfortable about their finances. Personal spending powers about 70 percent of the U.S. economy, and most economists say a fiscally fit consumer is critical to a strong economic recovery.

“There are signs of stability and growth,” said JPMorgan CEO Jamie Dimon.

The bank news comes after a holiday shopping season in which spending was the strongest since 2006, and auto sales grew 11 percent last year, the first gains since 2005.

Taken together, the spending indicators are the “strongest showing for consumers since the peak years of the last expansion,” and signal that the economy is “near a threshold of self-sustaining growth,” analysts at Citi Investment Research & Analysis said in a report earlier this month.

Economists and policymakers are waiting for signs that the economic recovery can power itself rather than rely on outside supports, like the Fed’s decision to buy hundreds of billions of dollars in government bonds to drive down interest rates.

The recent bank results are fueling that optimism.

Citigroup said loan losses fell 11 percent from the previous quarter as more of its customers kept up with payments.

It was the sixth straight quarter of declining losses, allowing the bank to release $2.3 billion from the reserves it sets aside for bad loans.