Permanent TSB has announced the sale of more than 6,000 non-performing mortgages to Glenbeigh Securities.
Nearly all of the loans sold were taken out on family homes and will be serviced by Pepper Finance on behalf of Glenbeigh Securities
The loans are valued at €1.3bn.
The bank says it is writing to all affected customers and has set up a helpline at 1890 500 223 or 021 601 3855.
They have also answered a list of frequently asked questions on their website.
The CEO of PTSB, Jeremy Masding, says customers will still be covered by Central Bank consumer protection codes when the loans are transferred:
Mr Masding said: "It enables those customers who have long-term treatments to continue with long-term treatments. The treatments are part of their loan terms and conditions and they travel into the transaction.
"The protections around those treatments also travel with the loan."