Formal:
* Tena koe! (For one person)
* Tena koutou! (For multiple people) - This means "greetings" but is also used as a farewell.
Informal:
* Haere ra! (For one person)
* Haere mai! (For multiple people) - This literally means "go there" but is used as a farewell.
* Kia ora! - This is a general greeting that can also be used as a farewell.
Other variations:
* Arohanui - This means "much love" and is a very affectionate farewell.
* Nga mihi - This means "thanks" and is a polite way to say goodbye.
* Ka kite ano - This means "see you again" and is a common farewell.
The best way to say goodbye in Māori is to use the phrase that is most appropriate for the situation. If you are unsure, it is always best to err on the side of formality.