Since many years, Portuguese companies and service providers which operate from a fix or permanent commercial establishment, which is open to the public (this includes providers of holiday accommodation) are legally obligated to make available a Complaint Book in physical form.
Since July 1st of this year, it is in addition obligatory to make availabe an Electronic or Online Complaint Book, which requires a registration on the following website (available in Portuguese and English):
https://www.livroreclamacoes.pt/en/web/guest/register
This allows consumers to raise a formal complaint on the following website (available in Portuguese and English)
https://www.livroreclamacoes.pt/inicio/reclamacao,
without the need to be at the commercial establishment, i.e. without requesting the physical Complaint Book.