Once you have completed your registration with Key Portfolio, you become an employee of an Umbrella Company. Your employment status is ’employee’.
This means you and Key Portfolio are bound by a contract of employment which remains in place even when you’re in between agency assignments. It means you’re entitled to full statutory employment benefits, such as sick pay, maternity pay, Employer’s Liability and Public Liability insurance cover.
You are not self-employed, so you don’t need to complete a tax return unless you have to do this for another source of income, or are otherwise instructed to do so by HMRC.