When a member joins your fund, you should ask for their TFN and provide it to the ATO.

A member isn’t required by law to give their TFN, however if they don’t:

• your fund can't accept member contributions for them, such as personal and eligible spouse contributions
• your fund must pay additional tax on their mandated employer contributions
• there may be administrative delays if the ATO can't identify the member from the other information you’ve provided
• the member may not be able to receive super co-contributions.