Schools in Northern Ireland overspent budgets by more than £62m in 2019.
More than 450 schools are also in the red, according to figures from the Education Authority (EA). This figure has been rising in recent years.
The EA clarified the financial position of schools in response to an enquiry from the UUP MLA Rosemary Barton.
There are just over 1,000 schools in Northern Ireland, all of which are given a yearly budget allocation by the EA.
Most of their funding is based on pupil numbers, but there are a number of other factors that decide how much money they get.
Collectively, 451 schools went over budget by a total of £62.6m in the 2018/19 school year.
The bulk of a school’s budget is spent on employing teaching staff.
Ms Barton said that many schools were in a “perilous” situation.
“From regularly talking to school principals across the country, I know that they have cut costs in almost every area,” she said
“Class sizes have grown, extra-curricular activities have been cancelled and valued staff have unfortunately been let go.
“Yet despite all those actions a record number of schools are now being left with no choice but to spend money that they simply do not have.”
A spokesperson for the Education Authority said schools and other services to children and young people needed more funding.
“We have been highlighting and acknowledging the financial challenges facing schools and the wider education sector for some time,” they said.