How can i autofill returns for my common law partner? do i have to be a representative to his trust account?

As per the Canada Revenue Agency (CRA) Preparing a tax return for a family member or a friend

Individuals can also use Auto-fill my return on behalf of a family member. If you prepare a tax return for a family member or a friend, you need to:

• be authorized by your family member or friend to use Auto-fill my return on their behalf. You will need a RepID, which you can get through the Represent a Client portal. The RepID identifies you with the CRA.
• give your RepID to your family member or friend so they can authorize you as their representative through their My Account. For more information on authorizing a representative, go to Authorize or cancel a representative.
• once you are authorized, you can use Auto-fill my return to access their tax information and file a return for them.

Each individual should enter their own CRA user ID and password to use this service. Auto-fill my return can be used for the current tax filing year plus the previous six tax years.

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