Post Office for Intermediaries will be closing for new mortgage applications on Friday 9 July.
The lender said all new business would be sold through the Bank of Ireland for Intermediaries channel after that date.
POI said it would still be available to support brokers with their existing deals.
New business mortgage products will be withdrawn at 9am on 9 July. All applications must be fully submitted and any outstanding Agreement in Principles must be converted to full applications by this date.
Cases submitted before this date will still have proc fees paid.
Bank of Ireland was approached for comment.
Samantha Partington is a freelance trade and consumer journalist writing about property and personal finance. Previously she worked worked for the Daily Mail and Property Week. She is the former deputy editor of Mortgage Solutions and editor of Specialist Lending Solutions.
Before becoming a journalist, Samantha worked as a mortgage broker and latterly for a mortgage, bridging and secured loan lender. Samantha is CeMAP qualified. Follow her on Twitter @SamJPartington1.