The charity Saint Vincent de Paul (SVP) received 30 calls an hour in August from parents worried about back to school costs.
The calls come as the overall demand for its services is up almost 20% compared to last year.
Almost half of the requests came from one-parent families, which SVP said reflects the very high levels of poverty experienced among these families.
Tricia Keilthy is head of social justice at SVP. She told Breakfast Briefing this year was particularly acute.
"It's been a very, very busy couple of weeks for the society as parents are preparing their children for back to school.
"And with costs so high, it's been very, very difficult for people on low incomes to meet those costs.
"That would be the same every year... but this year, given the added cost of living pressures where there's so much stress on family budgets due to energy bills and food bills, those costs have become even more difficult".
One day in early August, the charity took almost 450 calls.
One parents told the charity: "I’ve bought an iPad and books which cost me €1,400 this year, I still have their uniform to buy. I’m doing my best to keep it all together."
Another said: "The back-to-school allowance only covered the cost of my child’s tracksuit - he’s grown and needs new shoes and runners as well as a full school uniform."
Another parent added: "I can cover the bills and of course wanting to feed the kids, but it leaves me with nothing to cover their school costs. I’m really anxious, I’m losing sleep."
Ms Keilthy said many discussed the pressure of feeling like they weren't doing the best for their children.
"Many of the parents they felt really guilty, they felt a lot of pressure that they weren't able to provide for their children to get them ready for the school year.
"Some parents did receive the back to school clothing and footwear allowance, and the one-off increase in it this year had helped.
"But the reality is for many parents, that wasn't even close to meeting the full costs".
She said getting a first year student back to school costs around €1,500 - while the back to school allowance stands at €380.
"Then there was lots of other parents who don't qualify for the back to school allowance because they're earning just above the threshold, so they have to meet that full cost themselves.
"And that's a huge burden for those families", she added.
