Cracks in the resilient consumer narrative are starting to appear. Or so says Bank of America (BAC).

New data from BofA showed spending on the bank's credit cards decreased 0.3% in the week ending Sept. 23 compared to the same period last year. In fact, spending on BofA cards has been trending lower for several weeks now—and even lower when excluding auto and gas purchases.

"After a solid summer, spending appears to have decelerated post Labor Day," BofA US and global economist Shruti Mishra wrote in a research note published Thursday.

Mishra's team added: "Excluding gas and electronics, most other categories have slowed in the last month, especially the discretionary ones" such as furniture.

Gas prices have picked up recently, likely contributing to some of the increased spending on fuel, while the launch of the Apple iPhone 15 on Sept. 22 coincided with the strongest days of online electronics seen in roughly two weeks.

The sluggish Bank of America data comes after a summer-long onslaught of stronger-than-anticipated consumer data, which drove the economy to grow faster than many had expected. Federal Reserve Chair Jerome Powell has flagged that as a key reason, beyond inflation, that could prompt the Fed to hike interest rates again.

Read more: What the Fed rate-hike pause means for bank accounts, CDs, loans, and credit cards

But many economists have said consumers had already started to hold back and, thus, a slowdown is on the horizon. Other data out Thursday showed that might already be happening more than initially thought: Personal consumption growth in the second quarter, for example, was revised down to 0.8% from 1.7%.

Michael Pearce, Oxford Economics' lead US economist, said the revision downward suggests the consumer "is less resilient than previously imagined."

"We expect a weakening labor market and mounting headwinds to disposable incomes will drive a sharper slowdown in consumption and the broader economy over the rest of the year," he wrote in a research note on Thursday.

Meanwhile, EY's chief economist, Greg Daco, described the growing headwinds facing consumers as a "quadruple threat."

A looming government shutdown and an ongoing strike from the United Auto Workers could negatively impact economic growth, according to the economist. Also: Rising oil prices and the resumption of student loan payments are expected to weigh on spending.

Still, Daco noted, the current strength of the labor market, including the highest labor force participation since the onset of the pandemic, could help keep the expected consumer slowdown in check.

"Consumers are still willing to spend," Daco said. "But they are acting with more prudence ... So long as labor market conditions don’t rapidly deteriorate, the slowdown should be controlled, but a faster-than-expected labor market retrenchment could have dire consequences."

Josh Schafer is a reporter for Yahoo Finance. Follow him on X @_joshschafer.

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