Non-bank lender, Finance Ireland, is increasing its fixed mortgage rates by up to 0.75%.
The company said 5-year fixed rates will increase by 0.5%, while 3-year fixed rates will rise by 0.75%.
The changes will take place from this Thursday.
But the lender said that customers who have a loan offer by then will have until April 17th to close at the current rates.
"Cases at a pre-offer stage will have the new rates applied at loan offer," it said.
"Finance Ireland has a range of mortgage offerings and customers are advised to contact the lender or a broker or to view the CCPC website if they think they may qualify for a different product or a different rate on their mortgage."
The move will bring its highest 3-year fixed rate to 6.29% and its highest 5-year rate to 6.22%.
It is just a month since Finance Ireland last announced an increase in rates.
On that occasion it announced it was putting up its standard variable rate products by 1%.
In October it increased both variable and fixed rates for its mortgage products by between 1.5% and 2%.
Later the same month it also temporarily suspended fixed rate mortgage products for periods of 10 years or more to new applicants.
Non-bank lenders have been under greater pressure than the main banks to increase rates in recent months as they are funded from the wholesale markets, where rates have increased considerably.
The European Central Bank's Governing Council is due to meet again on Thursday and it is expected that it will raise interest rates by a further 0.5%.