Local elections 2023: How the BBC is reporting the results

Elections are taking place across England.

Local council and mayoral elections are taking place across England on 4 May.

Information on the Northern Ireland local elections on 18 May can be found here.

This will depend on the local authority. Some will start counting their votes straight after the polls close at 22:00 BST on 4 May. Others will wait until the following morning to start counting.

We are expecting about a quarter of councils to count overnight, with the first results coming in around midnight. Most of these councils will post their results in the early hours of Friday 5 May. Then there will be a lull before the remaining councils start counting at about 09:00 BST.

The first results from these councils are expected at midday. Most of these results will come mid-to-late afternoon, with a few expected later in the evening.

The BBC results service covers council and mayoral elections that are part of the regular election cycle. Election results are available at a council level.

In line with most media outlets, the BBC does not provide ward level results. There may also be parish, town or community council elections or council by-elections where you are. Results for these elections and ward level results can be found on your local council website.

The BBC uses data from the Press Association for its election results service, alongside some data it sources itself.

If a party has more than half of the councillors on a council, it is deemed to be 'in control' of that council. If no party has more than half of the council seats, the council is described as having 'no party majority'."

If a party did not have enough seats to control a council before the election but goes on to win more than half the seats on 4 May this is described a 'gain'.

This may be a gain from another party, or it may be that before the election no party had enough seats to control the council. In this case it is a gain from no party majority.

If the party already controlled the council before the election and they win more than half the seats again at this election this is described as a 'hold'.

Council control prior to the election is defined by the BBC, the Press Association (PA) and others as the party, if any, that had a majority in the days running up to the poll.

This may be different to the party that won at the last election.

For example, a party may have won control of a council at the last election but then have lost their majority in the meantime due to defections or by-elections.

If that party were to win the council again this year, the BBC would describe this as a gain for that party rather than a hold.

The change in the number of councillors for each party is calculated by comparing this election result with the result the last time these seats were contested.

For some councils, not all their seats will be contested at this election. Eighty-four of the 230 councils holding elections this year are only electing a third of their seats.

For most councils, the seats were last contested in 2019 but in some areas it was 2021 or 2022.

There are some areas where change is more difficult to calculate because there have been boundary changes or the number of councillors representing each ward has changed.

In cases like this, the BBC uses "notional results" to project what the previous result would have been if the new boundaries had been in place at the last election.

When the boundaries of council wards change, it is important to have an idea of how many councillors each party would have had if the new boundaries been in place last time the seats were contested.

This way, the change in the number of councillors elected for each party can be calculated on a like-for-like basis.

This is not an exact science. When boundaries are redrawn and an area is moved from one council ward into another there is no official record of how that area voted.

This is where the experience and expertise of analysts comes in.

To calculate the notional results, analysts use maps of the old and new boundaries. They look at the area, and use local knowledge and professional judgement to help them work out how people are likely to have voted.

Using this information, they recalculate the results of the last election to show how many councillors each party would have had if the new boundaries had been in place.

It is this figure that is used by the BBC to calculate change in these areas.

You can see if an area has had boundary changes in the 'About this council' section at the bottom of the council results pages or in the postcode lookup.

Banners appear at the top of the front page of the BBC News website, on indexes and stories related to the election.

Scorecards appear in election live pages, in stories about the election and on social media.

They are ordered by the number of council seats a party has won. This will change during the counting period as results come in.

When two parties are tied, the order is determined by how well the party did at the previous election when these seats were contested.

For most councils this is 2019 and so this is the result the BBC uses for the national scoreboards.

Mayoral elections are taking place in four areas of England: Bedford; Leicester; Mansfield and Middlesbrough.

The way mayors are elected has changed. They are now elected using a first-past-the-post system of voting. This means that the candidate with the most votes wins without the need for further rounds of counting or a redistribution of votes, as had previously been the case.

The BBC scoreboards sometimes show vacant seats. Vacant seats are those which are left vacant after this set of elections.

They are often seats where the election is postponed because one of the candidates dies during the campaign or no candidates stand.

In the case of councils that were electing only a third of their councillors, some seats may be vacant because the incumbent has died or resigned and that seat was not up for election this time around. In these cases a by-election would be held at some point in the coming weeks.