The banking group, which includes Lloyds and Halifax, said the closures were the result of lower customer visits.
The announcement will reduce the number of Lloyds Banking Group branches to 1,475, according to Unite Union.
Unite said closing all 41 Lloyds Bank branches and seven Halifax branches would mean thousands of customers would be denied access to essential services and cash.
The union also added that the closures could lead to up to 178 job cuts.
Unite also said he believed there should be a legal commitment for the banking industry to protect public access to cash and in-person banking services.
Lloyds Banking Group Retail Director Vim Maru said: “Like many other businesses, we have seen people use our branches less frequently in recent years, and this decline continues.
“Our branches remain a fundamental part of how we serve our customers, but we need to ensure that the size of our branch network reflects the number of customers who want to use them. ”
Unite General Secretary Sharon Graham said: “Lloyds Banking Group’s announcement of the closure of 48 additional bank branches is a complete betrayal of the communities and staff who have long supported this highly profitable business.
“This industry needs to start taking its corporate social responsibilities seriously and stop neglecting its obligations to its customers and its workforce.
“Banks are leaving people behind in a rush to close bank branches and forcing consumers to use cashless to increase their mega-profits. It’s a classic example of putting profits before people.
Where does the Lloyds Bank branch in Somerset close?
Lloyds Banking Group will close a branch in Somerset.
It will close its branch in Crewkerne.
The branch will close from March 7, 2022.
See the full list of UK closures.