'costs incurred' = 'coûts supportés' , maybe.
But then, that does not go well with 'efficacement'. If the sentence allows it, you could say 'les coûts devraient être efficacement répartis' .
Can you give the complete sentence, please ?
the complete sentence is "our costs shall be efficiently incurred (double R) and should be charged back to the users on a non-discriminatory basis"
I have got this one too "Information regarding the costs incurred by us for this purpose shall be made publicly available".