Was unter eligible costs zu verstehen ist, wird im FP6 Model Contract, Annex II, Art. 19.1 definiert:
- Eligible costs incurred for the implementation of the project must fulfil all of the following conditions:
a) they must be actual, economic and necessary for the implementation of the project; and
b) they must be determined in accordance with the usual accounting principles of the contractor; and
c) they must be incurred during the duration of the project as identified in Article 4.2 except for the costs incurred in drawing up the final reports referred to in Article II 7.4, which may be incurred during the period of up to 45 days after the end of the project or the date of termination whichever is earlier; and
d) they must be recorded in the accounts of the contractor that incurred them, no later than at the date of the establishment of the audit certificate referred to in Article II.26. The accounting procedures used in the recording of costs and receipts shall respect the accounting rules of the State in which the contractor is established as well as permit the direct reconciliation between the costs and receipts incurred for the implementation of the project and the overall statement of accounts relating to the overall business activity of the contractor; and
e) in the case of contributions made by third parties established on the basis of an agreement between the contractor and the third party existing prior to its contribution to the project, and for which the tasks and their execution by such a third party are clearly identified in Annex I, the costs must:
i) be incurred in accordance with the usual accounting principles of such third parties and the principles set out in paragraph d) above;
ii) meet the other provisions of this Article and this Annex; and
iii) be recorded in the accounts of the third party no later than the date of the establishment of the audit certificate referred to in Article II.26.
Ungleich früheren Rahmenprogrammen werden keine Kostenkategorien mehr von der Europäischen Kommission vorgegeben. Die üblichen Buchhaltungsgrundsätze der jeweiligen Vertragspartner sind die Grundlage, um die Kosten zu determinieren.
Die weiteren Kriterien für die Erstattungsfähigkeit von Kosten werden im "Guide to Financial Issues relating to Indirect Actions of the Sixth Framework Programmes" (Abschnitt 2.1.2, S. 24 ff.) beschrieben.