Wealthsimple offers joint Managed investment accounts, joint self-directed accounts, and joint Cash accounts. These accounts have tax implications since they are non-registered accounts.

Each year joint accounts are issued tax slips based on the account's activities. Joint account tax slips are issued in the name of all account owners, however, they will only contain the SIN of the individual designated as the “primary” account owner (the “inviter”).

All owners of the joint account must determine the correct amount of income from the account to report on their individual tax returns.

Income refers to different activities in different types of joint accounts:

• Joint Cash accounts: Income refers to the interest earned by the account.
• Joint investing accounts: Income refers to all taxable amounts earned by the account (including dividends, distributions from ETFs, capital gains/losses, fully paid lending income, and more).

Each owner must report their proportional share of account income. This is based on how much they each contributed to the joint account.

You can read more from the CRA here.