https://www.treasury.gov.au/sites/default/files/2019-07/at_g...
"What transactions are covered by the cash payment limit? The limit applies to all cash transactions equal to or in excess of $10,000, except for those that meet the conditions specified in the draft Currency (Restrictions on the Use of Cash—Excepted Transactions) Instrument 2019. "
I don't think this is going to affect somebody paying for split rent in cash...