Paying down credit-card debt appears to be on the upswing.

Consumers cut their outstanding revolving debt -– overwhelmingly credit cards -– by an annualized, seasonally adjusted rate of 10.5 percent in May, the Federal Reserve reported Thursday. That’s on the heels of an 11.8 percent drop in April. Revolving credit is a line of credit allowing consumers to pay all or part of an outstanding balance, and, as the balance is paid, it becomes available to spend again as credit.

But it might be premature to say that consumers have been scared straight.

The monthly consumer credit numbers tell only part of the story because it’s not yet known how much debt banks or merchants will charge-off, or remove from their books because they’ve deemed it uncollectable. The Fed’s charge-off numbers are released quarterly, and the first quarter’s 10.1 percent rate tied for the highest since the beginning of 1985, the latest period for which figures are readily available.

“Unfortunately we won’t know until the charge-off data comes out for the second quarter whether the reduction was actually due to consumers paying down their debt or the banks writing bad debt off the books,” Odysseas Papadimitriou, a former Capital One executive who is now founder and chief executive of credit-card research Web site Cardhub.com, said.

In the first quarter, for example, about 40 percent of the decline in credit-card debt was due to charge-offs, Cardhub.com said.

And though consumers did pay down $36 billion in credit-card debt in the first quarter, that’s still 23 percent less than they repaid a year earlier, it said.

Another reason for the drop in outstanding revolving debt: lenders have been tighter with credit with existing cardholders, giving them less rope to get in over their heads, a new study shows.

New credit-card limits from banks are just 40 percent of what they were in 2006, according to Equifax. And even year-over-year reductions in average credit limits -– to $4,000 from $4,600 -– means 13 percent less credit available for cards with the same credit score, the credit-data business said.

Finally, consumer bankruptcy filings nationwide totaled 770,117 in the first half of 2010, up 14 percent from a year earlier, according to the American Bankruptcy Institute. The bankruptcy process cancels many debts.

“All these factors suggest there is less credit in the system,” said Equifax, which has credit files on nearly 200 million U.S. consumers.

Indeed, there’s evidence consumers with active cards are paying them down, one study shows.

Though home-equity lines that consumers once used like personal ATMs are shrinking, credit-card debt per borrower is falling nationally, statewide and in the Chicago area, according to TransUnion.

Credit card debt per borrower in the Chicago area averaged $5,119 in the first quarter, down 10 percent from a year earlier and 6 percent from the fourth quarter, the credit-reporting firm found.

“We anticipate the decreasing trend in credit card debt that started in the second quarter last year to continue well past the second quarter this year,” TransUnion director Ezra Becker said.

Meanwhile, personal savings rates as a percentage of disposable personal income were 3.5 percent in the first quarter of 2010, down slightly from 3.7 percent in the year-ago quarter, according to the U.S. Bureau of Economic Analysis. But it’s up significantly from the 1.2 percent rate in the first quarter of 2008.