ICS Mortgages is to increase its fixed rate owner-occupier mortgages - effective from January 9, 2026.
This marks the first lender to increase rates this year.
The lender - which is owned by Dilosk - said the increases will see its fixed rates rise by between 0.25% and 0.45%, depending on loan-to-value bands.
ICS said the revised rates will apply to three-year and five-year fixed rate products and reflect prevailing market conditions.
Existing fixed-rate customers will not be affected, it added.
Ray McMahon, Chief Commercial Officer at ICS Mortgages, said that while it continually seek opportunities to support borrowers through competitive pricing and innovative products, these fixed rate adjustments reflect the realities of the increase in swap market pricing over the past two months.
"We remain committed to supporting our customers and broker partners through clear and timely communication," he added.
Commenting on the increase, Seán Corbett, Director of SYS Mortgages, said the decision has surprised the market, with ICS citing changing market conditions as the driver of the increase.
But he said that while any upward rate movement naturally raises concerns for borrowers, there is no need for panic.
"ICS, like a number of non-bank lenders, prices its mortgages based on what's known as the "Swap" rate, which reflects the cost of borrowing in wholesale markets. Those rates have risen in recent months, and that explains the adjustment we’re seeing here," he said.
"This does not automatically signal a broader shift across the mortgage market and we do not expect the main retail bank lenders to follow ICS’s move. They fund a significant portion of their lending through customer deposits rather than wholesale borrowing, which gives them far greater insulation from short-term market volatility," Mr Corbett explained.
"Looking ahead, while it's unlikely that the European Central Bank will reduce rates further in 2026, there is also no indication of any sharp upward movement. As things stand, the very competitive fixed rates currently available are unlikely to disappear overnight," he added.
He said that for borrowers, the key message is to stay informed but not alarmed.
"Isolated pricing changes by individual lenders does not mean the market is turning, and there are still strong options available for those willing to shop around and seek advice," he added.
