List seats in parliament refer to the seats that are allocated to political parties based on the number of votes they receive, rather than being elected from a geographical constituency. In some countries, all members of parliament are list members, while in others, a more complicated system is used. There are two main types of party list systems: closed list and open list. In a closed list system, each political party has pre-decided who will receive the seats allocated to that party in the elections, so that the candidates positioned highest on this list tend to always get a seat in the parliament while the candidates positioned very low on the closed list will not. Voters vote only for the party, not for individual candidates. In an open list system, voters can choose individual candidates from the party list.

The number of list seats each party gets is the difference between a partys total allocation of seats in parliament and its number of constituency seats. The exact method of allocating seats in party-list elections varies between countries, with different apportionment methods that may favor smaller or larger parties.

In the UK, nearly all MPs are members of political parties, and the House of Commons is made up of a total of 650 seats. MPs are elected from geographical constituencies, with each constituency selecting one candidate to be their representative in parliament.

In New Zealand, election candidates can become members of parliament by contesting electorates or being on a party list. Candidates on a party list can become list MPs if their party gets at least 5% of the party vote or wins one electorate. A partys total number of electorate and list MPs will be about the same as its share of the party vote.