In a statement in response to criticism of its concessionary Bus Scheme, the company said that over the last five years demand has increased every year for the service - on a concessionary basis - from Letterkenny Post Primary centre area.
There was a shortage of concessionary seats last year and the situation is the same this year.
Bus Éireann says it has 53 concessionary seats available and there were 76 pupils requesting seats this year.
Existing families don't get preference over new pupils when it comes to concessionary seats as is clearly stated in the terms.
The company says however that a review of the scheme is currently been undertaken at the Department of Education and Skills.
Bus Éireann operates the Post Primary School Transport Scheme on behalf of the Department of Education & Skills (DoES), in accordance with the rules and criteria of the scheme laid down by the Department and outlined on the websites of Bus Éireann and DoES.
Bus Eireann says that the availability of concessionary transport may vary from year to year, is not available on public scheduled services, and cannot be guaranteed for the duration of a child's Post Primary school education cycle.