It's time to start applying for tax back if you're entitled to it, a tax expert has said.
Taxback.com Business Development Manager Marian Ryan has said almost 600,000 people could be due a refund.
People can claim tax refunds up to four years after the tax year is finished.
Ms Ryan told The Pat Kenny Show the cut-off means people are running out of time to claim for 2019.
"There is a slight bit of a deadline - when it comes to PAYE taxes, like the everyday worker like myself, you can claim a tax refund - so you can file your tax return up to four years after the tax year is finished," she said.
"So, at the moment we can claim refunds for '19 right up until 2022; but once the end of the year comes, 2019 closes off on us.
"If there's a refund sitting there waiting for us it's gone forever, you can't claim it.
"There's a bit of urgency, but four years I suppose isn't too bad."
Ms Ryan said people don't have to make a claim, but it's worth finding out if you're entitled to anything.
"I would always, always advise people to be proactive when it comes to your taxes and file a tax return every year," she said.
"There's a level of apathy there... there's no obligation for us to do it.
"Out of those 800,000 people, almost 600,000 are either due a refund or that their taxes are balanced at the moment.
"Balanced means when your employer took all your taxes for you for 2022, everything was correct.
"When you're balanced it doesn't take into account things like you're medical expenses.
"Everybody in the country's going to have things like your medical expenses, and all the other different tax credits and reliefs that you can use to boost your refund.
"Worst-case scenario is you take five minutes to file your tax return and they say, 'Thanks very much for filing your return.'
"Best-case scenario is that there's going to be something there that you missed out on that will trigger refunds."
'Really simple process'
Ms Ryan said people don't understand how simple it is to claim refunds.
"The process is actually really simple; the biggest part for people is actually sitting down and figuring out what can I claim and what I'm entitled to," she said.
"That's the part that people miss out on - there's a huge lack of awareness out there of our entitlements."
Ms Ryan said it is not a necessity to include receipts.
"There is a portal there, a receipt tracker, so you can upload them there," she said.
"There's no obligation, it's similar to self-assessment, to actually send in your receipts with your return.
"You just simply need to put in the figures, if you want peace of mind you can upload the receipts as you go".
Ms Ryan said authorities can come looking for proof if there are no receipts included.
"The Revenue do have six years after returns filled where they can come back and look for evidence of an expense," she said.
"The possibility of an audit looms even more so I suppose if you put in very high expenses.
"Say, for example, a lot of people would come to use to claim back on fertility treatment - that's tens of thousands of euros.
"So, we would always say even though you don't have to put in the receipts with it, it's best to do so."
Incapacitated Child Tax Credit
Ms Ryan said one largely unknown credit is the Incapacitated Child Tax Credit.
"It's €3,300 a year, it's actually increasing to €3,500 in January," she said.
"It's for any parent who has a child that has a diagnosis of a life-long illness.
"Say, for example, if your child was diagnosed with autism this year, your child may be four years of age, it's a life-long illness.
"We can actually claim back your tax credit retrospectively back to 2019, so there could be a refund there of maybe €13,000.
"Any time there's a major life event, generally there'll be a taxable refund in the background," she added.
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