Australia

Section 7 states:

The Senate shall be composed of senators for each State, directly chosen by the people of the State, voting, until the Parliament otherwise provides, as one electorate….

Section 8 states:

The qualification of electors of senators shall be in each State that which is prescribed by this Constitution, or by the Parliament, as the qualification for electors of members of the House of Representatives; but in the choosing of senators each elector shall vote only once.

Section 41 states:

No adult person who has or acquires a right to vote at elections for the more numerous House of the Parliament of a State shall, while the right continues, be prevented by any law of the Commonwealth from voting at elections for either House of the Parliament of the Commonwealth.

Excerpts from the Commonwealth of Australia Constitution Act (1900, last amended 1977)

Section 93 states:

…all persons:

• (a) who have attained 18 years of age; and
• (b) who are:
  • (i) Australian citizens; or
  • (ii) persons (other than Australian citizens) who would, if the relevant citizenship law had continued in force, be British subjects within the meaning of that relevant citizenship law and whose names were, immediately before 26 January 1984:
    • (A) on the roll for a Division; or
    • (B) on a roll kept for the purposes of the Australian Capital Territory Representation …shall be entitled to enrolment [and to vote]...

Excerpt from the Commonwealth Electoral Act (1918, last amended 2005)