Penalty rates

Penalty rates are extra pay under an Australian modern award or enterprise agreement for unsocial hours — typically evenings, weekends, and public holidays.

They are award-specific. There is no single national penalty-rate percentage, and they are not the same thing as overtime (extra time outside ordinary hours). A Saturday loading and an overtime rate can both apply, or only one of them, depending on the instrument.

For a US reader, the nearer idea is a shift differential, not FLSA overtime. Do not treat “time and a half on Sundays” as an Australian default unless the relevant award actually says so.