Med det forbehold, at selve retten til erstatning følger direkte af fællesskabsretten, når disse betingelser er opfyldt, skal staten erstatte det forvoldte tab efter nationale erstatningsregler, idet betingelserne i de nationale lovgivninger for erstatning af tab dog ikke må være mindre fordelagtige end dem, der gælder for tilsvarende søgsmål efter national ret, og ikke må være udformet således, at de i praksis gør det umuligt eller urimeligt vanskeligt at opnå erstatning (dommen i sagen Test Claimants in the FII Group Litigation, præmis 219, og dommen i sagen Test Claimants in the Thin Cap Group Litigation, præmis 123).
Indeed, subject to the right of reparation which flows directly from Community law where those conditions are satisfied, it is on the basis of the rules of national law on liability that the State must make reparation for the consequences of the loss and damage caused, provided that the conditions for reparation of loss and damage laid down by national law are not less favourable than those relating to similar domestic claims and are not so framed as to make it, in practice, impossible or excessively difficult to obtain reparation (Test Claimants in the FII Group Litigation, paragraph 219, and Test Claimants in the Thin Cap Group Litigation, paragraph 123).