Postal customers have been reminded that the deadline for using stamps purchased before the euro-changeover is January 1st 2003.
The majority of other euro-zone countries will continue to accept pre-euro stamps up until 2010.
An Post spokesman Mr John Foley said; "We made it very clear in the lead-in to the introduction to the euro that people had a year in which they could use what would be described as dual denomination stamps (in pence or euro), and that after the end of the first year of the euro people would have to use stamps which were only denominated in euro.
"That's still the situation so our advice to people who have stamps dually denominated is to use them quickly," he said.