A spokesman for the building society says:
“These changes, which are permitted under the terms and conditions of the accounts, are a reflection of market conditions and the need for us to carry out our business prudently, efficiently and competitively.”
The landlords affected in this case - who are owners of multiple properties - are customers of the society's former specialist lending arm called the West Bromwich Mortgage Company. It is a wholly owned subsidiary of the West Bromwich Building Society.
George Spencer, chief executive at property and technology company Rentify, said:
"Landlords with West Bromwich Building Society will be reeling from the news that their mortgage rate is set to jump by two percentage points, even though there has been no movement in interest rates for more than four years.
"This adds a considerable £330 per month to the mortgage payment on a £200,000 loan, which will significantly impact landlords' profit margins.
"Landlords with other lenders will be concerned that they will follow suit so it is important to be vigilant."
