Social security contribution in Portugal
In order for the social department to calculate how much social you need to pay as a freelancer you need to declare your income every quarter, for eg I will declare my income for Jan, Feb and Mar in the month of April you can also declare income from outside Portugal as well. After submitting your declaration of income on the social website you will get a document "Documento Único de Cobrança" .
You need to pay this between the 10th and 20th of the following month. This document will provide you with an entity and reference number for payment which can only be done through a Portuguese bank account or at the ATM with a Portuguese bank account.
If you forget to declare your income for some reason there is a document automatically generated for €20 every month.
