We have a stash of more than €110m in foreign currency lying around our homes.
New research reveals that many of us don't bother changing our money back into euro after travelling abroad.
A survey by the travel money specialists No 1 Currency has revealed that 87pc of Irish adults have one or more types of currency sitting at home.
Irish people who have travelled outside of the eurozone over the last 12 months returned home with almost €100 each in foreign currency, according to the survey.
It means that there is more than €110m in foreign currency lying idle in households around the country.
Of the adults who have one or more types of foreign currency sitting at home, almost half (45pc) intend to hold on to it until their next travels.
Only one in five admitted to changing it back to euro as soon as they arrived home.
The survey also showed that of those who travelled outside of the eurozone, the UK is the most popular destination (44pc) followed very closely by the US at 42pc, Australia (9pc) and Canada (8pc) with a further 7pc visiting Asia.
"While many people prefer to hold on to their leftover currency to use on another trip, it can all add up and, if exchanged back to euro, could make the difference of an extra €100 towards the Christmas present list over the next couple of weeks," said Simon Phillips, the head of retail for No 1 Currency in Ireland and the UK.
He pointed out that after every trip abroad, most of us end up with a few sterling notes or US dollars in the bottom of our bags or at the back of our wallets.
However, with more and more people traveling outside of the eurozone to the US, UK, Canada and Australia, all of this currency adds up in people's homes across the country, Mr Phillips said.
No 1 Currency recently launched a new service called click and sell, where people returning from holidays can log on to www.no1currency.ie, select the currency and amount they want to sell, and bring their foreign currency to one of its stores to exchange their currency for euro.
Meanwhile, recent figures from the Central Statistics Office showed that more than 1.8 million outbound trips were undertaken by Irish residents in the second quarter of this year, which was an increase of 1.8pc over the same period last year.
The average length of stay on outbound trips was 7.3 nights.
The UK remains the most popular destination for travel in terms of number of trips, followed by Spain, and France .
Holidays accounted for over half (55pc) of all outbound trips, while almost a quarter were for the purpose of visiting friends or relatives.
Irish residents spent a total of €887m on holidays, €238m on visiting friends or relatives and €204m on business trips, the figures revealed.