If you’re receiving gift funds from a relative (typically!) most banks will require they write a letter confirming that they’re giving you the funds, suggested wording is as follows:
To whom it may concern,
I <<insert full name>> am gifting unconditionally to my <<insert relationship>> <<insert full name of gift recipient>> the amount of $XX,XXX.00
This gift is without requirement for repayment and is not interest bearing.
If your gift funds do require repayment have a chat a with your broker about this. And if the lender requires a statutory declaration or a specific lender form – we’ll let you know.
To see if gift funds would be helpful or relevant to your situation – have a read of this blog on how much deposit you’ll need: https://www.uploans.com.au/blog/2017/01/29/how-much-do-i-need-as-a-deposit/