AIB is increasing interest rates on new fixed rate mortgages by 0.5% from later today.
It is the first of the three main banks to raise mortgage rates in the wake of rises announced by the European Central Bank in September.
The increase will apply to new fixed rate mortgages, with existing fixed rate and variable rate mortgages unaffected.
Customers who draw down a new mortgage by November 14th can avail of the previous rates.
The new rates will be applied to existing customers who are entering a new fixed rate period after October 14th.
The change will take affect across the AIB Group which includes AIB, EBS and Haven.
In a statement, the bank said: "These changes will not affect any of the bank's variable or tracker mortgage rates, while existing fixed mortgage rates are also not affected."
AIB said a monthly repayment on a new €100,000 five-year green fixed rate mortgage, with a loan to value of 50% to 80% over a 25-year term, will be €455.91.
The previous monthly repayment would have been €431.01, it added.
While, Trevor Grant from the Association of Irish Mortgage Adisvors said, "It is good to see that AIB, EBS and Haven are allowing applicants who have been loan approved up to 4 weeks to close out on the mortgage they have applied for.
"This decision is welcome and follows extensive lobbying from mortgage brokers throughout the country when Finance Ireland initially chose not to offer such notice.
"This will enable hundreds of mortgage applicants to close on their new homes or secure a much sought-after mortgage switching deal."