Western Australia wants to reform the GST carve-up in a way that would net the state billions of dollars more each year, with Treasurer Rita Saffioti arguing the Commonwealth must reward economically successful states to encourage development.

Saffioti backed a NSW push to have the amounts handed to the states from the national goods and services tax take determined on a per capita basis, as part of what she said should be a national debate about how the GST encouraged economic growth.