Self assesment for referral bonuses?

Hi, Do I need to do a self assesment for recieving over £4000 in referral bonuses from various companies (banks mainly)? If so what does this come under? Self employment as sole trader? Does that mean I have to register as a sole trader just becase I signed up people through referrals? Thanks

Hi Kenny,
If the income has not been taxed at source under PAYE then yes you will need to declare this in a tax return.
Thank you.