All food and beverage establishments must have a complaint book, in accordance with Decree-Law No. 371/2007 of 6 November.

The establishment must display, in a clearly visible location and in easily legible characters, a sign with the following information: "This establishment has a complaint book".

This book will be provided immediately and free of charge to the customer whenever requested. If the complaint book is not immediately provided to the customer, the customer may request the presence of the police authority to overcome this refusal or for the authority to note the occurrence and forward it to the competent entity responsible for supervising the establishment.

Whenever a complaint occurs, a copy must be sent to ASAE (Food and Economic Safety Authority), the competent entity to supervise and initiate any administrative offence proceedings.