The self assessment client page allows you to manage all of your Self Assessment clients and their income sources in one place.
You can add a client by clicking the Add Client button and following the steps outlined in this article.
You can access their businesses or properties by clicking on the relevant entity listed in the Businesses column. Then from their account you can to add and manage transactions and update the client’s settings.
You can also add additional business by clicking the Add businesses button next to the ITSA client.