One mortgage advisor has said we're heading into a period of "sustained interest rate increases".
Martina Hennessy, managing director of doddl.ie, said people should act now to avoid repayment hikes.
Some rate holders who are coming to the end of their current rate face increases of up to €1,500 a year to lock in for a new five-year rate.
They will be paying close attention to the European Central Bank (ECB), who may decide to implement a proposed 0.75% increase in rates this week.
This would follow a 0.5% increase in July.
Irish banks did not pass on a previous hike to customers, but we are not expected to escape for a second time.
Martina told The Pat Kenny Show the best way to save money is to act now.
"In terms of getting a quote, or in terms of understanding if you can save, the key thing is to understand what rate you're on now.
"There's many websites, including our own like doddl, but the CCPC also.
"Within two minutes of being on that site you'll see what other rates are there for your mortgage amount, your loan-to-value.
"And then there is an application process to go about switching your mortgage.
"That's where you need advice, you need your hand to be held".
She said while it can be daunting for some people, there is also an onus on lenders.
"The lenders have a requirement to ensure if you're switching your mortgage, that the mortgage is still affordable for you.
"So they will look for your income docs, they will look for your payslips.
"But relative to the amount you can save - particularly again in the current environment where most customers are trying to lock down lower rates for longer to safeguard against interest rate increase - it'll be time well spent.
"It's really important now for mortgage holders to act to avoid unnecessary repayment hikes, and to look to switch their mortgage.
"Or indeed look to see what other rates are available from their own lender".
She said while rates are going up, people have time.
"If you look now there's a window of time before rates start to increase.
"But this is the start of it... we're heading into a timeline of sustained interest rate increases.
"So it's not just that now we have a small window: it's to act now, but to be mindful that rates are going to increase going forward.
"So what's best for you and your household, how can you lock down security of repayments? And really that's to fix - and fix in the medium to long-term".