Opening and Closing a Business Activity By Dennis Swing Greene, in Business · 12-02-2021 01:00:00 · 0 Comments Whether for profit or pleasure, the truth is that there are many people who choose to be sole traders as a way to make a living. More than one out of five Portuguese workers are self-employed, a percentage that places Portugal within the highest level of entrepreneurs in the EU. For a person to operate as a sole trader, there are some preliminary requirements that must be met with Tax Authority and Social Security Administration before starting up a business operation. Opening a business activity