You may also work as an independent self-employed trader. An independent trader who sells work agrees to accept assignments independently, and is neither directed nor supervised by the party providing the work. A self-employed person may work as a sole trader, as a freelancer, or as the representative of a company, and is then personally liable for self-employed pension contributions (YEL) and other insurance costs.
The mode of operation is irrelevant when deciding whether a worker is an employee or self-employed. If the formal definition is employment is satisfied, then you are an employee regardless of anything that you may have agreed.
Some signs of self-employment: