I think it's different in any country.
In Italy WTS is a giuridical entity or a corporation and have a Social Statute and based on this they obtain an agreenment with govern authotity in 1989 to operate a s a non profit corporation.
The reason for that agreenment is to obtain sovvention from the govern (so far not yet)
The Social Stature has a full list of code for the members(JWs) and their relationship with the Organization.
Not to mention that Social Statute is not delivered to the JWs to allow their acknoledgment, it's stored in the secret Congregation file.
Based on the Social Statute JW becomes member of the Organization at baptism, when he/she shout "YES" on the 2 question (especially the second one).
Still , on the Social Statute there's a chapter (Art.5) stating that a JW may dismiss itself from the Organization as corporation.
Two years ago an exJW (a lawyer) started a lawsuit against WTS Italy, as he would like to dismissis from the corporation but not from the JW religion , and he claim the court that the announcement in the congregation "XY in no nlonger a JW" is a social discrimination and a retention of indiviual religion freedom.
After that many JW in Italy sent a "dismission from the corporation (Art. 5)" letter asking not to be discriminated treathening going to the court.
We'll see in some months how this will go. In Italy timing for civil action are incredible long.
