The CRA considers amounts in box 20 and box 48 of the T4A slip as self-employment/business income.
If you entered a T4A slip in your return with amounts in box 20 or box 48, you must complete a Form T2125: Statement of Business Activities. Only minimal entries are required; the business name can be your name and the business address can be your home address. And you need to enter an Industry Code. Click on the link found in TurboTax and choose the code most closely associated with your type of business.
You will need to "edit" the information that has transferred from the T4A to the Business Statement. To do so, go to:
https://turbotax.community.intuit.ca/replies/3282160
