Rolled out to BofA's millions of customers over the summer, Erica helps users with a host of simple transactions such as money transfers and balance enquiries.

Colorado-based Erik Underwood, the founder of a service called My24HourNews.Com, has filed a trademark suit against the bank.

Underwood registered his own virtual assistant, called E.R.I.C.A (electronic repetitious informational clone application) in Georgia in October 2010.

His E.R.I.C.A acts as a search engine for an entertainment news site. On the site it is described as an "artificial intelligence mobile search engine that infuses software and holographic digital technology seamlessly together; to create an environment where your digital device is alive and interactive with the consciousness of E.R.I.C.A."

According to the Charlotte Business Journal, Underwood's attorney sent BofA a cease-and-desist letter in May before filing a complaint with the US District Court in Colorado on 11 September.

Underwood is seeking damages from the bank as well as reimbursements for profits lost.

BofA says it named its bot Erica after the last five letters in its name, securing its own trademark in 2017 for the service, which it has pumped an estimated $60 million into.

The bank says that it also used an attorney to investigate whether the Erica trademark was available for use.

In a declaration filed last month, the lawyer, Randel Springer, says: "I understood that, because of the way in which Bank of America was developing its new virtual financial assistant, customers would need to be logged onto Bank of America's online or mobile system when using it, and therefore would be aware that they were using a service provided by Bank of America, and not by Mr. Underwood."