According to AFP:
The 16 Commonwealth realms which share the same royal family — including Britain, Australia, Canada, New Zealand and Jamaica — must all pass an identical law before the changes can come into effect, unless UK legislation covers it for them.
They have all done so except Australia, said Jim Wallace, the deputy leader of the British parliament’s upper House of Lords.
Commonwealth realms rushed to agree the changes after Prince William — the elder son of Prince Charles and next in line to the throne after his father — got married in April 2011.
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