H&R Block sued against Block, formerly known as Square, on Thursday, claiming that the new name infringed on its trademarks.
The name change was revealed earlier this month by Block's CEO, Twitter co-founder Jack Dorsey, as the business moved to grow beyond its payment service into new sectors, including blockchain.
H&R Block, on the other hand, accused the corporation of "stealing Block's name in order to co-opt the reputation and goodwill that Block has earned through decades of hard work." in a federal lawsuit filed in Kansas City, Missouri.
Block did not respond to a request for comment right away.
Consumers are likely to be confused by a similar name, according to H&R Block, which has referred to itself in certain commercials as "Block" since 2015.
Since Block purchased Credit Karma Tax, now known as Cash App Taxes, last year, the two companies have become direct competitors in tax preparation services, according to the report. According to the lawsuit, Cash App Taxes' logo, a green square with rounded sides and a dollar sign are confusingly similar to H&R Block's green square design.
H&R Block is requesting a court injunction prohibiting Block from using the name or emblem.