How your vote is used to elect members of the Senedd

Published 22/04/2021   |   Last Updated 06/05/2021   |   Reading Time minutes

Did you know that each person in Wales is represented by not one, but FIVE representatives in the Senedd?

This blog explains where, how, and when they are chosen.

Where? Constituencies and regions

Wales is divided into 40 constituencies of roughly equal population.

Each of these constituencies belongs to one of the five regions in Wales. Four members of the Senedd are chosen to represent each region.

If you live in Wales you’ll belong to a constituency and a region, so will be represented by one constituency member of the Senedd and four regional members.  You can find out which region and constituency you belong to here.

How are they chosen?

Members of the Senedd are chosen by the people of Wales in an election once every five years. When you vote in a Senedd election you make two choices; one for an individual to represent your local constituency and one for a political party or individual to represent your region.

Two distinct electoral systems, (First Past The Post and The Additional Member System) are applied to decide who wins!

First past the post

This method is used to choose the constituency representatives. It’s very simple – the candidate with the highest number of votes wins and therefore will represent the constituency in the Senedd.

The First Past The Post system is used in UK parliamentary general elections and most local government (council) elections.

The Additional Member System

The method for electing the candidates that represent a region is a little more complicated. Bear with us and it should become clear!

Each region has eight constituencies - the chosen members from these are likely to belong to political parties.

Imagine we have four political parties - let’s call these Yellow, Red, Green and Blue – in Region A.

In all regions, the constituency (First Past the Post) seats are counted first. So, for example, in Region A we get the following First Past the Post results and:

  • 6 of the constituency members elected belong to the Yellow party
  • 2 to the red
  • and 0 to green or blue.

For your regional vote, you would have been asked to choose a party, so imagine that the results of the regional vote are as follows:



Number of Votes










The number of votes needs to be divided by the number of times the party is already represented in  that region plus 1, to give what we call the ‘quotient’. Using the information above we quotients would be:





7,000 ÷ 7 =1,000


6,300 ÷ 3 = 2,100


3,000 ÷ 1 =3,000


2,000 ÷ 1 = 2,000


The party with the highest quotient number (in this case Green) then delegates a candidate for the first regional seat. The formula is reapplied until all four regional seats are filled.

If you didn’t understand any of that, don’t worry, all you really need to understand is that it’s a process that aims to make the Senedd more representative of the views of the population as a whole.

When can you vote?

The next Senedd election is on 6 May 2021.

Find out more about the Senedd Election.