You will only be asked for proof of residence for subscriptions with a preferential rate, when you subscribe online or in person:
o resident subscription: proof of address
o worksite pass: a K-Bis and a worksite certificate stating that the company engages in the demolition or total construction of a tower
o motorbike pass: a vehicle registration document
o merchant subscription: an extract from the 2059E tax return or a specific certificate from the manager
o All information available in the subscription form.