FTSE 100 company list: where the official one lives and why copies go out of date

By MarketFrame · Published 27 October 2026

Short answer: use the index provider's list, and check its date

The FTSE 100 belongs to FTSE Russell, LSEG's index business. Its Ground Rules for the UK Index Series name FTSE International Limited as the benchmark administrator. FTSE Russell describes the index as "the largest 100 UK companies by full market capitalisation". Two primary sources are worth bookmarking:

• FTSE Russell (lseg.com) for the rules, each review announcement and the FTSE 100 historic additions and deletions document.
• The London Stock Exchange's FTSE 100 constituents table (londonstockexchange.com) for the current members in a sortable table.

Everything else, from a news article to a shared spreadsheet, is a copy. A copy can be accurate, but only up to the date it was made. For background on what the index is and how it works, see our guide to what the FTSE 100 index is.

Why a copied list goes stale: the quarterly review in plain English

Section 8.1.1 of the Ground Rules says the series "is reviewed on a quarterly basis in March, June, September and December". At each review, eligible companies are ranked by full market capitalisation (the total value of their shares), and two thresholds decide who moves:

• A company outside the index is added if it has risen to 90th or above.
• A company in the index is removed if it has fallen to 111th or below.

The gap between 90th and 111th is deliberate. The rules say they are designed to "provide stability" while keeping the index representative, so a company sitting around 100th place does not move in and out every quarter.

Changes take effect after the close of business on the third Friday of the review month. Companies that leave the FTSE 100 normally move into the FTSE 250.

Reviews are not the only time the list changes. FTSE Russell's FTSE 100 page says unplanned events "such as initial public offerings and corporate actions, are reflected in the index series daily". A takeover can remove a company in any month.

So a list copied in May can be wrong by late June. A list copied the day before a takeover completes can be wrong the next morning.

Five checks before you trust any FTSE 100 list

1. Who published it? FTSE Russell and the London Stock Exchange are the sources. A blog, a broker page or a marketing site is a copy, however tidy it looks.
2. What is the as-at date? Look for a date on the table itself as well as on the article. Without one, you cannot tell how old the list is.
3. Which review does it reflect? Review changes take effect in March, June, September and December. If a list is older than the most recent review, check that review's changes before you rely on it.
4. What do the identifiers mean? A company name, a share-line name and a ticker are three different things. Where you can, match on the ticker.
5. What does the list leave out? A constituents table shows the members on one day. It does not show who has just left, who is near the thresholds, or the many London-listed companies outside the index.

Most copied lists fail the second check. They look current, but nothing on the page says when they were true.

How to read the official constituents table

The London Stock Exchange's FTSE 100 table has seven columns: Code, Name, Currency, Market cap (m), Price, Change and Change %. Here is what each one tells you:

• Code is the short ticker, for example REL for RELX. It is the most reliable thing to match when comparing two lists, because company names get shortened and rebranded.
• Name is the listed share line, which may not match the brand name you know. RELX appears as "RELX PLC ORD 14 51/116P": the company, the type of share (ORD, ordinary shares) and its nominal value.
• Currency is the currency the price is quoted in.
• Market cap (m), Price, Change and Change % are market data that move during the day. You don't need them to check membership. The table can open sorted by the day's movers, so sort by Name or Code before you compare.

You can't predict a review from the market cap column either. The review ranks companies using FTSE Russell's own data, taken at a fixed cut-off (the Tuesday before the first Friday of the review month), and applies its own eligibility tests.

A worked example: one company out and back in within six months

FTSE Russell's review announcements, and its FTSE 100 historic additions and deletions document, record each change with its date. The historic document has columns for the date, the company added, the company deleted and notes. Here is one company in 2026, named exactly as FTSE Russell names it:

1. 4 March 2026: the March quarterly review announcement confirmed that IG Group Holdings and Lion Finance Group would join the FTSE 100, and that "Easyjet and Hikma Pharmaceuticals will leave the FTSE 100 Index and enter the FTSE 250 Index". The changes took effect from the start of trading on Monday 23 March 2026.
2. 2 September 2026: the September quarterly review announcement confirmed that "Easyjet and Ithaca Energy will join the FTSE 100 Index", with Entain and Persimmon leaving. Those changes took effect from Monday 21 September 2026.

Now apply that to copies. A list saved in February 2026 included Easyjet, and it was right at the time. That same list was wrong from 23 March to 20 September. A list saved in the summer leaves Easyjet out, and has been wrong since 21 September. Both look equally official. Only the date tells you which one to believe.

The notes column in the historic document is worth reading too. Some entries are marked "Corporate Event" (for example, a takeover) or "Fast Entry". These are changes made outside the usual review pattern.

You can follow easyJet's news coverage on its MarketFrame company page.

Common mistakes: confusing the FTSE 100 with all companies listed in London

• Treating the FTSE 100 as the whole market. Under the Ground Rules, the index is drawn from securities listed on the Main Market of the London Stock Exchange, and only the largest 100 that qualify get in. Many listed companies sit outside it.
• Mixing up the FTSE 100 and the FTSE 250. Rule 7.2.1 defines the FTSE 250 as "the next 250 UK companies ranked by full market capitalisation" outside the FTSE 100. Together they make up the FTSE 350. A move between the two reflects a change in rank at a review and nothing more.
• Trusting a row count. A table with 100 names can still be last quarter's 100 names.

Where MarketFrame fits: browsing company news rather than a membership list

We don't publish a membership list, because it would go out of date in exactly the way this post describes. FTSE Russell and the London Stock Exchange are the places for that. MarketFrame reads the UK business news on each FTSE 100 company every morning, checks which stories are really about that company and scores the tone of the coverage.

• FTSE news is the daily hub, with the latest day and the sectors.
• The daily overviews show each day across the index, including the most positive and most negative coverage.
• The company and sector pages list every company we cover and 17 sectors, each with a history from 30 September 2026.

Important: a company's place in the index says nothing about its share price or news tone

Being in the FTSE 100 says how large a company was at a review date. It is not a verdict on the company or a signal about where its shares will go.

The same goes for news tone. A MarketFrame tone score runs from -10 (clearly bad news for the company) to +10 (clearly good). It describes the tone of news coverage. It is not a share-price forecast and it is not investment advice. Index membership and news tone are two separate facts, and each should be checked against its own source. This post is general information. It does not advise buying, selling or holding any share.

Questions people ask

Where is the official list of FTSE 100 companies published?

FTSE Russell, part of LSEG, runs the index. It publishes the rules, each review announcement and a FTSE 100 historic additions and deletions document on lseg.com. The London Stock Exchange shows the current members in its FTSE 100 constituents table on londonstockexchange.com. Whichever you use, check the date.

How often does the list of FTSE 100 companies change?

The FTSE UK Index Series Ground Rules say the index is reviewed quarterly, in March, June, September and December. Changes take effect after the close of business on the third Friday of the review month. FTSE Russell also says unplanned events, such as corporate actions, are reflected in the index series daily, so a takeover can change the list in any month.

How many companies are listed on the London Stock Exchange compared with the FTSE 100?

The FTSE 100 has 100 constituents by definition: the largest 100 qualifying UK companies by full market capitalisation. The total number of listed companies changes all the time, so we do not quote one here. If you need it, use the London Stock Exchange's own statistics and note the as-at date.

What is the difference between a FTSE 100 company and a FTSE 250 company?

Size, measured at each review. The Ground Rules define the FTSE 250 as the next 250 UK companies by full market capitalisation outside the FTSE 100. At a review, a company joins the FTSE 100 if it has risen to 90th or above and leaves if it has fallen to 111th or below. Companies that leave the FTSE 100 normally join the FTSE 250.

Can a company drop out of the FTSE 100 between reviews?

Yes, through a corporate event such as a takeover. FTSE Russell says corporate actions are reflected in the index series daily, and its historic additions and deletions document marks those changes as "Corporate Event". A fall in rank on its own is dealt with at the next quarterly review, where the 90th and 111th thresholds apply.

Sources

• FTSE Russell: FTSE UK Index Series Ground Rules (v17.3)
• FTSE Russell: FTSE 100 index page
• FTSE Russell: FTSE 100 historic additions and deletions
• LSEG: FTSE UK Index Series Quarterly Review March 2026
• LSEG: FTSE UK Index Series Quarterly Review September 2026
• London Stock Exchange: FTSE 100 constituents table