How firmlist Calculates Its Company Figures

The definitions and rules behind the figures on firmlist's company pages, and what those figures can and can't tell you.

This applies to the pages for SIC codes, industries, postcode areas and monthly registrations. Every figure on them is counted directly from Companies House records. Nothing is estimated, modelled or scraped from websites.

Where the data comes from

All figures come from the Companies House register: its bulk data products, plus its public API for details of newly registered companies. How often each kind of data is updated is shown at the bottom of this page.

The pages are built from a snapshot of that data, so each one says which month its figures are as of. For exact, current figures, every page links to the same companies in the live search.

Which companies are counted

Only companies on the live register are counted. Dissolved companies aren't, because Companies House's bulk company data barely includes them, so any figure for them would be misleading.

"Active companies" means companies whose Companies House status is exactly Active. That excludes companies with a proposal to strike off, and companies in liquidation, administration or another insolvency procedure. The headline count on each page is this figure.

The On the register chart splits the live register into three groups:

Group	Companies House statuses
Active	Active
Proposal to strike off	Active – Proposal to Strike off
In insolvency or administration	Liquidation, administration, receivership, voluntary arrangement, and combinations of these

Status describes a company's legal position, not whether it is actually trading. An active company may be dormant. See UK Company Status Explained.

SIC codes

Self-declared. Companies choose their own SIC codes when they register and when they file confirmation statements. Nobody checks them, and some are out of date. See UK SIC Codes Explained.
Counted under every code. A company can have up to four SIC codes and is counted under each of them. Adding up the counts for several codes can therefore give more than the number of companies.
Pages. A SIC code gets its own page when at least 250 active companies use it.
Catch-all codes have no page. 99999 (Dormant Company), 74990 (Non-trading company) and the obsolete 7499 describe a company's state rather than an industry, so they get no page, although they still appear in lists.
Old codes. Descriptions follow the current (2007) SIC standard. Some companies still hold older 4-digit codes, which are counted as they are.

Industries

firmlist's own groupings. Industries such as "Technology" or "Construction" are groups of SIC codes chosen by firmlist. They are not an official Companies House or ONS classification, and other sources may draw the lines differently.
Exact definitions. Each industry page lists every SIC code it includes, so its figures can be reproduced.
Each company counted once per industry. A company with two technology SIC codes counts once towards Technology. A company with codes in two different industries counts towards both.
One industry per code. Each SIC code belongs to at most one industry.
Industries by area. Each area page lists all industries with their counts in that area, and each industry page lists every area. These use the same once-per-industry counting.

Locations

Registered office, not trading address. Location figures use each company's registered office address. Many companies register at their accountant's or a formation agent's address, so registered offices cluster in city centres. See UK Postcode & Location Search Explained.
Postcode areas, not towns or councils. A postcode area is the letters at the start of a postcode (M, L, BT and so on), and its boundaries don't match city or council boundaries. The M area covers Manchester and Salford but not Stockport, which is in SK. BT covers all of Northern Ireland, not just Belfast. The London overview covers the eight traditional London postcode areas, but parts of Greater London, such as Croydon (CR), Bromley (BR) and Harrow (HA), are in other areas.
Districts are the first half of a postcode (M1, CF10 and so on).
Large shared addresses. Some single addresses, usually formation agents or virtual offices, are the registered office of tens of thousands of companies. In a few areas, one postcode holds a third or more of all active companies. These are real registered offices, so they stay in the figures. But when one postcode holds 10% or more of an area's active companies, the area page says so, and Key facts that compare locations point it out.
Pages. A postcode area gets its own page when at least 1,000 active companies are registered there.
Unusable addresses. About 2% of active companies have a postcode missing or not in UK format. They are left out of every location figure but counted everywhere else.
Companies House default addresses. Companies House moves a company to its own default address (CF14 8LH in Cardiff, EH7 9HR in Edinburgh, BT1 9DY in Belfast) when its real registered office can't be verified, and most of these companies go on to be struck off. The address says nothing about where they are, so they are left out of every location figure, but counted in SIC, industry and monthly figures. The affected area pages say how many were left out.
Not included: Jersey (JE), Guernsey (GY), the Isle of Man (IM) and Gibraltar (GX). They appear in Companies House addresses but aren't UK postcode areas, and they have their own company registries.

Dates and company age

Incorporation date. All dates are the date a company was registered at Companies House. That is not necessarily when it started trading. See UK Company Age & Incorporation Date Explained.
Company age is measured from the date the figures are as of, and shown for active companies only.
Completed months only. Monthly figures stop at the last full month, so a part-month is never shown as if it were complete.
Still on the register. A month's registration count includes only companies that are still on the register. Companies registered that month that have since been dissolved aren't counted, so earlier months look lower than they really were.

Recently registered companies

Lists of recently registered companies show the 10 most recently incorporated active companies for that page, with each company's name, number, registration date and town. Any public Companies House record can be looked up in full in the search.

Key facts and UK comparisons

The Key facts on area, industry and SIC code pages are written automatically from the same figures as the rest of the page. Their UK-wide comparisons add up every UK postcode area, so they cover the companies with a usable UK postcode. A "times as common" comparison is only shown when the difference is at least one and a half times and is based on at least 200 companies.

Rounding and the live search

Rounded figures. Counts of 1,000 or more are rounded to three significant figures and marked "about" when rounding changed them, for example "about 49,700". The page figures are a snapshot, and the rounding stops them claiming more precision than a snapshot has.
The live search can differ. It uses the latest data with exact counts, so its figures can differ slightly from a page's. It also doesn't apply the default-address exclusion above: a search by postcode includes every company registered there.

Known limitations

SIC codes are self-declared and may be inaccurate or out of date.
Registered offices may differ from where a company actually trades.
Postcode areas don't match city, county or council boundaries.
An active status doesn't mean a company is trading.
Dissolved companies aren't covered, so historical registration counts are understated.
Industries are firmlist's groupings, not an official classification.