How a line gets drawn
Each page joins official records by an official identifier. Where no identifier joins two records, no line is drawn.
Linking a donor to a company
The Electoral Commission records a company registration number for some donors. That number is an official identifier, so the link to Companies House is made by number and labelled official ID. No donor is linked by name. Numbers are normalised before the join: spaces removed, letters upper case, all-digit numbers padded to eight digits.
Counts. 16,927 donations carry a company number, covering 4,156 distinct numbers. 3,082 (74.2%) match a company in the Companies House basic company data. (QUALITY.md, entry "2026-10-11: donors linked to Companies House by company number".)
Why 1,074 do not match. Most are eight-digit numbers beginning `00` to `05`, which are older companies. Numbers that do not match are held and are not shown as links.
Checking the link against the names
As a check on the number, we compare the donor name as recorded with the name Companies House holds now. A difference is not treated as an error: companies are renamed, use trading names, and donors abbreviate. Each company page shows both names and how far they agree.
| Agreement | Pairs | Share |
|---|---|---|
| Same after normalising | 3,030 | 73.5% |
| Very close (typos, punctuation, "and" and "&") | 444 | 10.8% |
| Close | 178 | 4.3% |
| Different | 473 | 11.5% |
Who controls the company
Controllers are taken from the Companies House register of people with significant control, current entries only. Where a controller is itself a company with a UK registration number, we follow it, up to three steps. We stop there.
- Companies and other legal entities are named, with the nature of control in the words of the register, made readable.
- Individuals are private people acting in a public register. They are counted at each step and never named. Their names and other personal details are not exported from our data at all.
- 2,749 of those have at least one current person with significant control on record. In this beta, 2,706 of the 3,039 companies with a page have a controller on record.
Who received the money
Recipients are named as the Electoral Commission records them where the recipient is a party or another organisation, or a person in elected office. Party is shown as text and never as a colour. Recipients who may be private individuals, such as party members, candidates and some campaigners, are described by type and not named.
Held for review
Before anything is written, every exported file is checked for the name of any individual controller. A company whose registered name contains such a name is held back and counted (43 in this export). A controller, recipient or recorded donor name that contains one is replaced with a note that it is held for review. A second check scans the built site and fails the build if any such name, anything shaped like a personal date, or a postcode appears.
What a line means
- Gave to. Stated by the Electoral Commission register of donations. Counted by accepted date and value as published.
- Controlled by. Stated by the Companies House register of people with significant control.
- No line. A shared name or address, a guess, or a link through a private person. Those are logged as leads, not drawn.
Links between records are matched by name and number. Check how each was matched.
What this does not show
- Why anyone gave, or what followed. A link between records does not show wrongdoing.
- Donors without a company number, and companies not in the live company data (most probably dissolved).
- Past controllers. The register extract holds current entries only.
- Anything after the retrieval date shown on each stamp.
See Sources for each file used, with its retrieval date and checksum.