For life insurance or capitalisation contracts where rights are expressed in units of account mentioned in 6° or 7° of article R. 131-1, the sum paid according to the contractual provisions is equal to the foreign currency or euro equivalent of the units or shares, based on the surrender value of these units or shares on the date stipulated for this purpose in the contract. This date may not be more than two months after the date on which the claim for benefit is submitted to the insurer.