identifier

identifier · Optional

Appears in

Organization

What is it?

identifier attaches a formal, machine-readable identifier to any schema.org entity. For organizations, this can be a registration number, internal system ID, industry code, or any other recognized identifier that distinguishes this entity from others. It accepts plain text, a URL, or a structured PropertyValue object that names the identifier system alongside the value.

Why this matters for AEO

AI answer engines resolve entity identity across data sources by matching identifiers. When two knowledge bases reference the same organization but disagree on details, a shared formal identifier (such as a DUNS number or LEI code) lets AI systems confirm they are referring to the same legal entity. This disambiguation is especially valuable for companies with common names or multiple international presences. Including identifier with a recognized system name increases the precision of entity resolution and reduces the risk of your organization being conflated with another entity in AI-generated answers.

What the specs say

Schema.org:identifier expects a PropertyValue, Text, or URL. The identifier property represents any kind of identifier for any kind of Thing, such as ISBNs, GTIN codes, UUIDs etc. Schema.org recommends using PropertyValue for structured identifiers where the name of the identifier system matters. [Source: https://schema.org/identifier]

Google: Not mentioned in Google's structured data documentation for Organization. Specific identifier fields like leiCode, duns, and taxID are separate schema.org properties that convey similar information in purpose-specific fields. [Source: https://developers.google.com/search/docs/appearance/structured-data/organization]

How to find your value

Choose the identifier type most authoritative for your organization's context:

• Company registration number — Government business registry (e.g., Companies House in the UK, SEC EDGAR in the US)
• DUNS number — Dun and Bradstreet D-U-N-S lookup
• LEI (Legal Entity Identifier) — GLEIF global LEI search at lei.info
• CIK (SEC Central Index Key) — SEC EDGAR full-text search
• Internal system ID — Your own ERP or CRM system
• Custom identifier — Any proprietary or industry-specific code relevant to your context

For standard identifiers that have dedicated schema.org properties (leiCode, duns, taxID, vatID, naics, isicV4), prefer those purpose-specific fields. Use identifier for identifiers that do not have a dedicated property.

Format and code

Plain text (minimal, low context):

{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Cloudflare",
  "identifier": "0001477333"
}

URL (links to an authoritative record):

{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Cloudflare",
  "identifier": "https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001477333"
}

PropertyValue (recommended: names the identifier system explicitly):

{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Cloudflare",
  "url": "https://cloudflare.com",
  "identifier": {
    "@type": "PropertyValue",
    "name": "SEC CIK",
    "value": "0001477333"
  }
}

Multiple identifiers (array of PropertyValue objects):

{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "HubSpot",
  "url": "https://hubspot.com",
  "identifier": [
    {
      "@type": "PropertyValue",
      "name": "SEC CIK",
      "value": "0001404655"
    },
    {
      "@type": "PropertyValue",
      "name": "DUNS",
      "value": "046866969"
    }
  ]
}

Webflow implementation

Static pages

Add the JSON-LD in Page Settings > Custom Code for your homepage or about page. The identifier value is static for most organizations. Use the PropertyValue format so that the identifier system is explicitly named.

CMS template pages

If you are publishing multiple organization entities (e.g., a directory of companies), store identifier values in CMS fields and output them in JSON-LD embed blocks. Map identifier name and value as separate CMS fields to produce the correct PropertyValue structure.

In Schema HQ

The identifier field allows adding custom identifier fields within the Organization schema editor. Enter both the identifier name (e.g., "DUNS") and the value to produce a properly nested PropertyValue object.

Real examples

{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Atlassian Corporation",
  "url": "https://atlassian.com",
  "identifier": [
    {
      "@type": "PropertyValue",
      "name": "SEC CIK",
      "value": "0001650372"
    },
    {
      "@type": "PropertyValue",
      "name": "LEI",
      "value": "549300RZ8CG4VAMHUR96"
    }
  ]
}

Related fields

• leiCode
• duns
• taxID
• vatID
• iso6523Code

FAQ

When should I use identifier versus leiCode or duns?

Use leiCode, duns, taxID, vatID, and other purpose-specific properties when the identifier type matches. Use identifier for identifier systems that do not have a dedicated schema.org property, or when you want to attach a custom or proprietary identifier.

Does identifier accept multiple values?

Yes. Pass an array of PropertyValue objects to attach multiple identifiers to one organization. This is useful for organizations with both a LEI and an internal ID that you want to expose to parsers.

Is PropertyValue always required for identifier?

No. Plain text and URL are valid. However, PropertyValue is recommended when you want parsers and AI systems to understand which identifier system the value belongs to. Without a system name, "0001477333" is ambiguous.