Typical consumers will visit a bank branch four times a year by 2022, turning instead to their mobile phones for services, according to forecasts.
At present, people visit seven times a year on average, industry analysts CACI have said.
It forecasts that contact with banks will rise - but primarily through apps, with desktop banking also shrinking.
Hundreds of branches have closed in the UK in recent years, with banks pointing to changing consumer habits.
Although the number of visits to banks may be falling, the proportion of those who use a branch, however infrequently, is relatively unchanged. This has prompted a warning from the forecasters that the public still see branches as having a role to play.
On Tuesday, the industry marked the 50th anniversary of the first cash machine, and many ATM manufacturers claim that new technology allows the most up-to-date machines to carry out 90% of all tasks conducted in a branch.
The latest CACI figures, which are used by the banking industry, estimate that banking app transactions - such as balance checks and payments - will more than double in the next five years.
These will not be simply be tasks that had been carried out in branches. Many customers - primarily high-income professionals - will shift from banking via computers, it claims.
Interactions made using a laptop or desktop will decrease by 63% between 2017 and 2022, it estimates.
All these shifts are happening faster than five-year forecasts made a year ago.
"The speed and convenience of mobile banking is a huge contributing factor to its ongoing popularity, especially as banks add more and more functionality to their apps. Understanding who is using it, and how, is key for banks to ensure it works for everyone," said Jamie Morawiec, associate partner at CACI.
"However, with more than half of the population still expected to visit a branch in 2022, the branch still has an important role to play.
"Banks and financial institutions must ensure that the function of the branch remains relevant, complements the digital channels, and meets the specific needs of the demographics that are using them."