To the extent clients are subject to a [required] equalization contribution under art. xxxx, 50% of the payment's portion which is billed as labor cost out of the invoice's total amount may be credited to the [required] equalization contribution for severe disability (art. xxxx)

In such cases, I always retain the source language term so that anyone can trace it back to what it actually is; then I pick a term that is used by pretty established soruces to designate the same item in the source culture (see links below)

I have done enough translations in which I couldn't for the world establish what something was originally called (e.g., because the text had been translated from another language and someone made up a term; esp. for legal issues, this is not at all helpful (since all research will have to be done back to the original source if it's used in court)