A self-assessment is system whereby HMRC collects income tax. When self-employed you will be responsible for paying your income tax to HMRC and you must declare it at the end of each ta year (5th April) by completing a self-assessment. You can complete this online via HMRCs website yourself or appoint a tax agent or accountant to do it on your behalf.  EEBS can help you with your tax return for just £99 plus VAT click here to start your return.