A Costco membership allows individual and business to buy items in bulk, from paper towels to mustard to detergent, at much lower prices than they’d find everywhere. (Costco’s gross margins are about 11%, compared to low 20s for discount stores and upper 30s for department stores.)

For Costco, memberships are an important source of income that go straight to its bottom line: In 2015, the company pulled in $2.5 billion in membership ship fees from 81.3 million members. Sam’s Club, the Wal-Mart Stores (WMT) unit that is Costco’s most direct rival, has said the fees are a “significant” component of operating income.

Costco currently charges $55 and $110 for a membership at two different levels. At Sam’s, the fees range from $45 to $100. But UBS analyst Michael Lasser, who recently met with Costco’s CFO and other executives, said in a recent research note he thinks they could go to $60 and $120 sometime early next year.

“The conditions are in place for Costco to bump up its membership fee early next year,” Lasser wrote. It would be the first Costco fee increase, an event that typically occurs every five years, since 2011. The only thing that would impede a hike, Lasser said, was the unlikely event of a slowdown in traffic.

Costco did not respond to a request for comment.

The time could be quite propitious for a hike. Costco is about to switch credit card partners, ending its long exclusive deal with American Express in two month to switch to Visa. A UBS survey found that 10% of respondents said they were not Costco members in part because the retailer did not accept Visa (V) or MasterCard (MA).

What’s more, Costco has been improving its merchandise, something that should keep drawing shoppers, even as Sam’s Club looks to win over Costco’s affluent customers with its own enhancements and e-commerce offerings. UBS’s Lasser noted that Costco has expanded its fresh items assortment, products that drive shopper traffic, including on-site bread baking at some stores.