Revenue is advising people who have not yet posted their Local Property Tax return, to do so today.
Tuesday is the deadline for postal payments, but as Monday is a Bank Holiday, those intending to use that method have been advised to do so in today's post.
People who opt to file online have until May 28 to complete the return electronically.
Vivienne Dempsey, Property Tax Manager with the Revenue Commissioners explained what will happen if anyone fails to file their postal return on time.
"If your return is postmarked Tuesday, we'll actually accept it as having been received on time," she said.
"So yes, we're encouraging you to do it today, but if you're doing it over the weekend, once the postmark is Tuesday, we'll still accept it as being on time.
"If you miss that deadline, then you're definitely into the extended timeframe, which is up to the 28th, and you then have to file online."