Getting started
The mailing address at the start of the tax return is the contact address that the CRA should use if they need to contact you by mail. You don't actually have to live there.
You can go back to the self-employment section and edit your business. As you continue through, you'll get back to the question where it asks if you use your home address for your work. You can change that to "no" and then you'll get a spot to enter an address. You can put your home address here, if it's different from the contact address that you entered at the start. You can still claim home office expenses even if you use a PO box (or some other arrangement) for a mailing address instead of your home address.
