JPMorgan Chase & Co. has begun informing financial-technology companies that it will start charging for access to customers’ bank-account information, ending the free data feeds that have underpinned much of the sector’s growth. The largest U.S. bank has sent pricing sheets to data aggregators such as Plaid and MX outlining fees that could collectively reach hundreds of millions of dollars a year, people familiar with the matter said. Levies will vary by use-case, with payments-focused firms facing the highest rates, and are slated to take effect later this year. Platforms that rely on real-time bank data—including PayPal’s Venmo, cryptocurrency exchange Coinbase and brokerage Robinhood—could see their economics squeezed and may pass the costs on to consumers. Many fintechs currently obtain the data for free through aggregators that connect their apps to customers’ bank accounts. JPMorgan says the charges reflect the substantial investment it has made in secure data-sharing infrastructure and are necessary to protect consumers from fraud. The move coincides with the banking industry’s legal challenge to a Consumer Financial Protection Bureau rule that would require lenders to provide customer data at no cost; the rule’s fate could influence when, and how steeply, the new fees are imposed.