Seven major charities, including the Irish Cancer Society, fear their funding will be hit if one and two cent coins are removed from circulation.
"It's a tough time for charities in general. We aren't funded by the government and need to fundraise for 95pc of our income," said the cancer charity's head fundraiser Mark Mellet.
The ISPCC, Goal Ireland, Diabetes Ireland, Cystic Fibrosis Ireland, Temple Street Children's Hospital and Oxfam Ireland have also said they will feel the difference at collection boxes if the coins are taken out of circulation.
Another charity has said it has made plans for the move.
"We started a dedicated coin collection on these specific coins with this in mind in early 2014 focusing on the connection of the numbers one and two to Type 1 and Type 2 Diabetes," said a spokesman for Diabetes Ireland.
"We felt we could resonate with consumers on this number linkage and it was promoted through our community … to date, this has raised almost €10,000 which is fantastic".
Many charities are no longer relying heavily on collections but may still feel the sting, a spokeswoman for Temple Street Children's Hospital explained.
"Whilst it's not a huge percentage of our income, we do know that one and two cent coins are donated at Temple Street bucket collections, and a lot of people who support us use bucket collections to do so, therefore it would affect us," she said.
One organisation, Change for Charity, is seeking to collect 1c and 2c coins before they are taken out of circulation, and said that the Central Bank's plan could give a short-term boost to their worthy causes.
"All coins donated are being divided equally between the Irish Heart foundation, Irish Autism Action, St Francis Hospice, Our Lady's hospice and care services, and Gaisce. The final fifth of the funding is being reserved for any other registered Irish charity to apply," a spokesman for the campaign said.
Dublin-based Senator Catherine Noone who proposed the idea to Government said that other countries that phased out copper coins did not witness a fall in donations.
"I think people, and charities, would be just as happy with one five cent coin donated rather than five one cent coins donated," she said.
Taoiseach Enda Kenny said the proposal wouldn't be the first time the country has seen a change in coinage.
"We've had this before with the farthings and the hapennies and the thrupenney pieces. They all went by the way so obviously the Central Bank will make it's own view known on that," he said.