Europe • ISO GG
Verify Guernsey companies via API
Know Your Customer Limited verifies Guernsey companies live from the Guernsey Registry, returning company data, controlling parties, and registry documents, with AML screening and ongoing monitoring. Free sandbox available.
What the API returns for Guernsey
When you create a KYB case for a Guernsey company, Know Your Customer Limited retrieves data live from the Guernsey Registry. A single integration returns the company record, the controlling parties and individuals, the shareholders and beneficial owners, and the registry documents, with AML screening on the entity and its associated individuals built into the same case.
Guernsey data and document availability
What the API makes available for Guernsey companies:
| Category | Available |
|---|---|
| Company data | Entity Name, Entity Type, Registration Number, Entity Status, Address, Registration Date, Previous Names, Other Names, Activity Type |
| Controlling entities & individuals | Name, Role, Address, Appointed On |
| Shareholders & beneficial owners | Not available |
| Documents | Retrieved by default: Registry Extract Available on demand: Certificate of Good Standing, Certificate of Incorporation, Annual Return, Re-Registration Form, Annual Validation Form, Annual Validation Form – Additional Information, Change of Director Form, Articles of Association, Memorandum of Association, Pre July 08 Incorporation Documents, Change of Reg Office Address Form, Resolution Form, Resolution Attachment, Foundation – Change of Particulars, Annual Renewal – Foundation, Foundation registration form, Charter, Councillors consent to act, Disenfranchised beneficiaries declaration, Guardian consent to act, LLP Incorporation form, LLP – Change of Particulars, Annual Validation – LLP, Change of Particulars, AV Amendment, Limited Partnership Registration Form |
AML, sanctions, and PEP screening on the entity and its associated individuals, and ongoing live monitoring with change alerts, are available for Guernsey as part of the same case.
How to verify a Guernsey company via API
The following example shows the complete flow: authenticate, search the Guernsey registry, create a KYB case, and retrieve company data and the ownership org-chart. All calls go to the sandbox base URL for testing.
The sandbox at https://api.knowyourcustomer.dev is free. Request access to get your client credentials.
# 1. Authenticate (OAuth2 client credentials)
curl -X POST https://api.knowyourcustomer.dev/connect/token \
-d "grant_type=client_credentials" \
-d "client_id=YOUR_CLIENT_ID" \
-d "client_secret=YOUR_CLIENT_SECRET" \
-d "scope=PublicApi"
# 2. Search the Guernsey registry
curl -X POST https://api.knowyourcustomer.dev/v2/Companies/search \
-H "Authorization: Bearer $TOKEN" \
-H "Content-Type: application/json" \
-d '{"name":"Guernsey National Bank","codeiso31662":"GG"}'
# 3. Create a KYB case
curl -X POST https://api.knowyourcustomer.dev/v2/Companies \
-H "Authorization: Bearer $TOKEN" \
-H "Content-Type: application/json" \
-d '{"rawname":"Guernsey National Bank","codeiso31662":"GG"}'
# 4. Retrieve company data and status
curl https://api.knowyourcustomer.dev/v2/Companies/CASE_ID \
-H "Authorization: Bearer $TOKEN"
# 5. Get the beneficial ownership org-chart
curl https://api.knowyourcustomer.dev/v2/Companies/CASE_ID/org-chart \
-H "Authorization: Bearer $TOKEN"
Replace YOUR_CLIENT_ID and YOUR_CLIENT_SECRET with your sandbox credentials, and CASE_ID with the caseCommonId returned in step 3.
Frequently asked questions about the Guernsey KYB API
What company data can I verify in Guernsey?
For a Guernsey company, the API returns the company record read live from the Guernsey Registry: the entity name, type, status, registration number, address, and registration date, along with the controlling parties, and the available registry documents. See the table above for the full Guernsey availability.
Does the API return beneficial ownership (UBO) data for Guernsey companies?
For Guernsey, the Guernsey Registry does not publish shareholder or beneficial-owner data, so the API returns the company record and the controlling parties and officers rather than a shareholder or beneficial-owner list. Where you need ownership for an entity in a jurisdiction that does publish it, the recursive org-chart (GET /v2/Companies/{caseCommonId}/org-chart) resolves it. See the UBO API.
Can I retrieve official registry documents for Guernsey companies?
Yes. The default document set for Guernsey includes Registry Extract, retrieved by default, with additional documents available on demand (Certificate of Good Standing, Certificate of Incorporation, Annual Return, Re-Registration Form, Annual Validation Form, Annual Validation Form – Additional Information, and more). List and download them with the documents endpoint (GET /v2/Companies/{caseCommonId}/documents).
Is there a free sandbox for testing Guernsey company verification?
Yes. The Know Your Customer sandbox at https://api.knowyourcustomer.dev is a free, high-fidelity test environment. Request free sandbox access to start testing.
The Know Your Customer Limited API covers 147 jurisdictions worldwide, including Guernsey. One integration, one set of credentials, one response schema across all markets. Browse all covered jurisdictions.
Related coverage: United Kingdom • Aaland Islands • Albania • Austria • Belarus • Belgium.
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