Schools are being forced to seek funding for disadvantaged students from the St Vincent De Paul, religious charities, community associations and parents' associations, a survey released at the NAPD conference has revealed.
They also rely on local credit unions, banks, past pupils' associations, and development associations to secure the funding they need to tackle disadvantage.
According to a survey of 199 school principals and deputy principals by the NAPD's disadvantage committee, 86 were forced to turn to the Saint Vincent De Paul to get the help they need for their disadvantaged students.
Only 18 per cent of those responding were from schools which are officially designated as disadvantaged.
According to the committee's chairwoman, Ms Aine O'Neill, the report is "an indictment of funding for our schools".
"A significant number of schools fund home/school liaison and resource/remedial provision from within their own resources," the report states.
"Schools also provide financial support for poor families, food, booklending schemes, resources, resource rooms and counselling etc from within their own resources or through fund-raising activities.
"This is especially true of those schools which indicated they were not in a disadvantaged area," the survey stated.
Additional resource hours and home/school liaison were "by far the most significant needs" identified by principals.
This was followed by the provision of in-service training for teachers, while supports for families such as counselling, parenting courses and psychological services were also considered important.
When asked to define disadvantage, 85 per cent said it related to specific learning difficulties, 83 per cent to special needs, 79 per cent family trauma or general learning difficulties, and 73 per cent emotional needs.