You are at least 18 years of age.
You have either a regular bank account or an e-bank account in you own name, with which you can receive Euro payments from European countries, paid from a regular bank.
You have your own private email address and Skype account.
You have a valid copy of a passport or a valid official nation wide ID card of the country you live and work.
You work as a free lancer, meaning you have an agreement with the company to complete a task. This can be a minimum number of hours but most of the time this will be a set number of messages, either weekly or monthly. Of course they will require a certain quality as well.
You have a good working computer, desktop or laptop (including mouse and keyboard), good and stable internet speed (including a good working modem and router) and a steady power line. A free lancer can never derive any rights from the fact one or more of those are malfunctioning. Same applies when you make mistakes, caused by your connection or your stuck laptop.
This is not something we made up. It is in the law. All these things are essential to be able to perform online tasks and are therefore your own responsibility.
It is even so that if you inform a company your laptop is broken, you have no right at all to demand you can work again once it has been repaired. If a company allows you so, that is a favor, not a right.