The consumer association argued that Belgian national law implementing the Gender Directive was incompatible with the principle of equal treatment for men and women. The ECJ agreed that allowing differences in insurance contracts linked to the gender of the insured was unlawful. It found that reliance by insurers on actuarial statistics associated with gender amounted to discrimination and was therefore incompatible with the fundamental principle of equal treatment. The ruling of the ECJ is final and there is no possibility of further appeal.

Differences in premiums and benefits in insurance contracts which are based on gender will no longer be lawful, and unisex premiums will apply, from 21 December 2012. Although occupational pension schemes were not mentioned expressly, the decision is likely to have a significant impact on the pensions industry, with annuity rates for men falling into line with those for women. The shorter transitional period than that recommended by the Advocate General means that insurers should review their policies and practices without delay. Insurers may need to use uncertainty premiums until they have sufficient data on issuing policies on the new basis. This could result in higher premiums or lower benefits for certain policyholders (female motorists and male annuitants being the obvious examples), with insurance generally becoming more expensive, due to stricter underwriting tests.