Questão jurídica principal
Whether the water/wastewater invoice was invalid because it was not drafted as a formal decision and lacked signature/reasoning.
Decisão extraída
The invoice was formally defective, but not null; at the latest the municipal council’s decision on the objection constituted a valid appealable decision.
Fundamentação extraída
A defective notification does not destroy the legal nature of the act. Nullity is reserved for serious defects. The appellant was able to object and have the matter decided.