have been the recipient of the Family Tax Benefit (FTB) for the previous financial year and have had your entitlement to the FTB payments finalised by Centrelink
ensure the person in your household who's registered as the FTB recipient lodges the application. The recipient is the person who receives correspondence on FTB from Services Australia.
NSW’s can be found here:
https://www.service.nsw.gov.au/transaction/apply-for-the-family-energy-rebate-retail-customers
Tl;Dr for eligibility: