--- title: "Deterministic matching" summary: "Deterministic matching decides a pair by an explicit rule — usually agreement on a strong identifier — and produces the same verdict every time with no score in between." canonical_url: https://entitybind.com/glossary/deterministic-matching last_updated: 2026-10-15 copy: full --- # Deterministic matching > Deterministic matching decides a pair by an explicit rule — usually agreement on a strong identifier — and produces the same verdict every time with no score in between. Canonical page: https://entitybind.com/glossary/deterministic-matching Last updated: 2026-10-15 Glossary · Matching methods ## How to read this The definition as the field writes it comes first, weaknesses and all. What Entity Bind does about it comes last, in its own paragraph, so you can take one without the other. [Filed under matching methods](https://entitybind.com/glossary#matching). By [James Rooney](https://entitybind.com/about), founder of Entity Bind · Last revised 15 October 2026 ## What deterministic matching means A deterministic rule is a stated condition: same LEI, or same registration number within the same register plus a name sanity check, or same VAT number. If the condition holds the pair matches; if it does not, the rule says nothing and the pair falls through to something else. There is no probability and no threshold to tune. Its strength is that it is auditable and cheap. A reviewer can read the rule, agree or disagree with it, and reproduce the verdict by hand; the machine reaches it without a model call, without network egress, and in constant time. Its weakness is brittleness: deterministic rules are silent on the records that lack the identifier, which in most real files is the majority of them. The dangerous form is deterministic matching on a weak key. Name plus country is a rule, and it is wrong often enough to be unusable in registers with dense name collisions. Registration number without its issuing authority is a rule, and it produces confident false positives across jurisdictions that reuse number ranges. Entity Bind runs deterministic identifier rules third in its cascade, after normalisation and retrieval, and checks register shape rather than string equality. Conflicting strong identifiers are a decisive non-match rather than a shrug. A record arriving with a company number or an LEI resolved at 100% (317/317) on the representative fixture of 2026-08-29, at one credit and no model spend. ## Where this shows up in Entity Bind Three pages where this term stops being vocabulary and starts changing an answer, a payload or a price. - [What is entity resolution?](https://entitybind.com/guides/what-is-entity-resolution): Entity resolution decides which records in one or more datasets refer to the same real-world entity, and joins them under a single stable identifier. - [How it works](https://entitybind.com/how-it-works): The seven-stage cascade in order, what each stage can settle on its own, and what it hands to the next. - [The API reference](https://entitybind.com/api): The REST surface: payloads, the decision outcomes, the error model, the usage block and the ceiling on the confidence field. The fastest way past a definition is a file: which of your rows are the same company, which of your existing matches we would not have made, and what we could not decide. [Start free →](https://app.entitybind.com/app?signup=1) ## The terms next to this one Each with its own sentence, because the next question is usually about the word beside this one. - [Probabilistic matching](https://entitybind.com/glossary/probabilistic-matching): Probabilistic matching scores a candidate pair by weighing the agreement and disagreement of several fields into a single number, then applies thresholds to that number rather than to any one field. - [Company number](https://entitybind.com/glossary/company-number): A company number is the identifier a register assigns to a company at incorporation, and it is unique only within the register that issued it — never within a country and never globally. - [LEI (Legal Entity Identifier)](https://entitybind.com/glossary/lei): The LEI is a 20-character ISO 17442 code identifying a legal entity that participates in financial transactions, issued through the Global LEI Foundation and published as open reference data. - [Match weight](https://entitybind.com/glossary/match-weight): A match weight is the log-scaled contribution one comparison makes to a pair's score, positive when agreement is evidence of a match and negative when disagreement is evidence against. - [False positive](https://entitybind.com/glossary/false-positive): A false positive in entity resolution is a pair of records asserted to be the same entity when they are not — the error class that corrupts data rather than merely leaving it untidy. ### Answered at length elsewhere - [Company identifiers explained](https://entitybind.com/guides/company-identifiers-explained) (Guide): Company number, LEI, CIK, ticker, SIREN and SIRET, DUNS, VAT, EUID and ISIN. What each identifies, who issues it, what it does not guarantee, and which ones actually decide a match. - [LEI](https://entitybind.com/identifiers/lei) (Identifier): One LEI names one legal entity worldwide, and most companies hold none. An agreeing LEI settles a match with no model call, a conflicting one against. - [Company number](https://entitybind.com/identifiers/company-number) (Identifier): A company number names a registration, not a company: 220 of 232 jurisdictions run more than one register, so it decides only once the register is named. ## The other 12 terms on this shelf How two records are compared and how the comparison is made cheap enough to run. Blocking, deterministic rules, probabilistic scoring, string distance. - [Normalisation](https://entitybind.com/glossary/normalisation) - [Transliteration](https://entitybind.com/glossary/transliteration) - [Blocking](https://entitybind.com/glossary/blocking) - [Candidate generation](https://entitybind.com/glossary/candidate-generation) - [Probabilistic matching](https://entitybind.com/glossary/probabilistic-matching) - [Fellegi–Sunter](https://entitybind.com/glossary/fellegi-sunter) - [m-probability](https://entitybind.com/glossary/m-probability) - [u-probability](https://entitybind.com/glossary/u-probability) - [Match weight](https://entitybind.com/glossary/match-weight) - [Fuzzy matching](https://entitybind.com/glossary/fuzzy-matching) - [Edit distance](https://entitybind.com/glossary/edit-distance) - [Jaro–Winkler](https://entitybind.com/glossary/jaro-winkler) Previous, alphabetically: [Deduplication](https://entitybind.com/glossary/deduplication) · Next, alphabetically: [Edit distance](https://entitybind.com/glossary/edit-distance) ## Evidence basis Internal fixtures only. The historical 2026-08-29 per-tier recording covers 317 GB companies with identifier-rich arrivals seeding the catalogue first; the context tier includes country and registered-town prose. Its legacy replay has no full-prompt-verified calls and cannot certify current calibration. The September 5 CI reports cover 1,176 labelled pairs and 705 records over 250 companies using offline stubs. These are not independent customer holdouts or live production validation; the 99% minimum-input product target remains unmet. Scope is company and organisation identity only — not people, vessels, bank-account ownership, sanctions or emissions. Results may not be used for eligibility decisions about individuals, including employment, credit and tenancy. ## Start with your own company records. Create your workspace, verify your email and run your first company file. The Free plan needs no card. Create API keys in your workspace when you need an integration. [Start free](https://app.entitybind.com/app?signup=1) · [All 64 terms](https://entitybind.com/glossary) 300 credits. No card. For a guided review of your file, explore [the Merge Safety Sprint](https://entitybind.com/audit-pack). --- Historical results on an internal UK fixture with a preloaded catalogue. The September 5 replay has no full-prompt-verified calls and cannot establish current calibration. No independent customer holdout or global coverage claim. Entity Bind resolves companies and organisations only. It does not resolve people, vessels, bank-account ownership, sanctions exposure, emissions or geolocation, and its results may not be used for eligibility decisions about individuals, including employment, credit and tenancy. This is the Markdown copy of https://entitybind.com/glossary/deterministic-matching, assembled from the same data the page renders and carrying every sentence, table row, figure and question the page's main content carries. The HTML page is canonical; it adds the layout, the navigation and the interactive parts (the ask panel, the forms), which a copy can name but not run. Every page on the site, with a line on each: https://entitybind.com/llms.txt.