Self Assessment registration - setting up as a sole trader

Hello. I want to register as a sole-trader for a new small business and already submit a self-assessment tax return due to receiving rental income on a property (unrelated to the new business). Do I need to register for self-assessment for the new business (& get a new tax ref no.) or can the income tax return for it be submitted as part of the existing one I use for the rental income? Thanks.

Hi Neil
In order to register as a sole trader, you must register for Self Assessment. As you have already registered for Self Assessment for another reason, you will need to register again.
The guidance here explains:Register as a sole trader.
Thank you.

Thank you, much appreciated.