The API uses a secure, tokenised 'handshake' between the companies’ servers, eliminating the need for Intuit customers who use QuickBooks, Mint and TurboTax to share their Wells Fargo usernames and passwords, and the need for Intuit to store them in order to retrieve bank account data.

The issue of customer data sharing has been a sticking point in bank relationships with fintech competitors. Earlier this month, a host of US fintech firms - including Betterment, Kabbage and Ripple - set up an industry group to push for consumers' rights to share their bank financial data with third parties.

Banks have been reluctant to provide access to data to upstart competitors and say that the practice of customers giving third parties the ability to login to their accounts for this purpose poses a security risk.

Wells Fargo first bid to break the deadlock last summer through an API arrangement with small business accounting software outfit Xero but the Intuit deal - and Intuit's Chase partnership - have given fresh impetus to the effort to get banks and technology companies working together to serve their shared customers.

Brett Pitts, head, digital, virtual channels, Wells Fargo, says: "This agreement creates a much better experience for our shared customers, gives them greater control over their financial data, and enhances the efficiency of the data-sharing process."

Pitts emphasises the flexibility of the Wells API, which will let customers choose which account information they share with Intuit from the second half of the year.

Tayloe Stansbury, CTO, Intuit, says: "We’re pleased to join with Wells Fargo to provide our shared customers with greater access and control of their financial information."