Fewer than 1pc of mortgage holders switch providers despite many saying they are concerned about value.
A survey of 200 mortgage holders by MyMortgages.ie found almost a third said interest rates were a continuous source of worry.
Joey Sheahan, head of credit at the company, said Ireland's mortgage-switching market remained too small despite figures from the Banking and Payment Federation showing that remortgage or switching approval volumes rose by almost 32pc last year.
He said figures from the Central Bank showed that less than 1pc of mortgage customers had switched.
Those who do switch providers can save on average between €2,000 and €3,000 a year, according to MyMortgages.ie.
"I think people are put off by their first mortgage experience, which for many was stressful as they tried to juggle a rental property and get a sale agreed on their new home," said Mr Sheahan.
"The second time around should be a lot more straightforward.
"Of course there will be forms to fill, but the rewards for a little admin can be in the region of thousands."
He said in many cases there would be no early breakage fee for leaving a fixed rate and advised people to check with their bank.