If you're a parent with a child in school, the odds are you have received a letter from the school asking for a voluntary contribution.
Most public schools around the country request a contribution from parents, typically to fund miscellaneous school expenses such as photocopying or art materials.
A Barnardos survey from last year found that a majority of parents are asked to pay a voluntary contribution at both primary and secondary level.
While most pay under €100 for their children in primary school, the survey found that 55% of secondary school parents pay over €100. Some parents reported paying contributions many times higher than that.
According to the Department of Education, voluntary contributions from parents of pupils "are acceptable provided it is made absolutely clear to parents that there is no question of compulsion to pay and that, in making a contribution, they are doing so of their own volition".
The Department adds: "The manner in which such voluntary contributions are sought and collected is a matter for school management; however their collection should be such as not to create a situation where either parents or pupils could reasonably infer that the contributions take on a compulsory character."
A letter recently published by TheJournal.ie, however, claims that one school said non-payment of a fee for school expenses could result in restricting access to a book rental scheme, or a child not being brought on school trips.
"This is not a voluntary contribution and all pupils are expected to pay in full," the published letter notes.
"It's absolutely rampant"
Victoria White, columnist with the Irish Examiner, spoke to Newstalk Breakfast about the issue of voluntary contribution, and impact they have on parents and children.
She observed: "I have certainly seen it in schools local to me - I have seen an invoice coming in on the phone for two children for nearly €700 in a primary school.
"I also know of schools in which the children that haven't paid the voluntary contribution are singled out, and a letter is handed to them [...] It's absolutely rampant."
Victoria cited the constitutional provision that the State "shall provide for free primary education".
"This is such a serious situation, that you have to look at a situation whereby we would ban voluntary contributions," she argued. "What has happened here is the capitation for each child going to primary school - and secondary school, certainly primary - is just too low."
However, she also stressed that she encourages raising additional money for schools through the likes of bake sales or Christmas fairs.
"I don't think fundraising is a problem," she told Shane. "Fundraising does have a dual effect of actually bringing the school community together [...] You genuinely do have opt-in, opt-out.
"The difference is getting an invoice, or a bill, for things that the school itself has decided to do [...] The parents didn't get opt-in, opt-out."