Following the merger with Charter Court Financial Services which completed in October, the remaining second charge operations will be merged with those at Precise Mortgages in Wolverhampton.
OSB has not set a date for when the closure will take place or when it will stop accepting new applications.
It told Specialist Lending Solutions: “We propose that Prestige Finance will continue to accept new business applications and will advise of dates in due course.
“All new business will need to be completed – but we will advise of a date when we know further.”
The Competition and Markets Authority (CMA) approved the merger with Charter Court last year and the lender added that no additional regulatory approvals were required to complete the closure.
In a statement to the stock market, OSB said the move had come as a result of an “attractive offer” to purchase its Prestige House property in Hertfordshire, which it has accepted.
The lender confirmed that jobs could be lost but did not give a figure for how many people might be affected.
“Where possible, OSB will seek to review opportunities to reallocate staff from discontinued roles arising from the disposal of Prestige House and the operation of the Prestige brand to other appropriate roles, including those being created from organic growth,” the statement said.
“However, the intended actions outlined in this announcement are likely to have an impact for those employed in Prestige House and by the Prestige brand.
“OSB confirms that the employment rights, including pension rights, of all such employees will be fully safeguarded.”
According to the most recent data available for the first half of 2019, the Prestige second charge loan book was valued at £372.8m, broadly level with the December 2018 total of £368m.
In its first half trading update, the lender said new lending issued by Prestige matched redemptions on the active book and those closed books it has acquired.
OSB group managing director of mortgages Alan Cleary (pictured) said: “The attractive offer for Prestige House has led us to consider this proposed restructure which, we believe, would enhance the overall second charge loan proposition.”
“We are actively engaging with our key intermediary partners on this proposal to ensure minimal disruption.
“We are also consulting with our colleagues at Prestige Finance who are directly impacted by this proposal to ensure they receive the support they need,” he added.