01 / IDENTIFYING A COMPANY
Company identifiers
What SIREN, SIRET and the NAF code mean, where to find them and how to avoid typing mistakes.
- SIRENWhat is a SIREN number and how to find itThe 9-digit format, who gets one, where it appears and how to find a company's SIREN from its name.
- SIREN · SIRETSIREN vs SIRET vs NIC: what is the difference?The company and its establishments: 9 or 14 digits, the role of the NIC and the right number for each use.
- SIRETHow to check a French SIRET numberThe 14-digit format, spotting typing mistakes and the difference between a valid SIRET and an active establishment.
- NAF CODENAF / APE code explainedWhat a code like 62.01Z means, who assigns it, what it is used for and why it cannot settle a collective agreement on its own.
02 / VAT AND COUNTRIES
VAT, Belgium and Switzerland
VAT numbers in France, Belgium and Switzerland, with the format used in each country.
- VATFrench VAT number: format and how to check itThe French, Belgian and Swiss formats, the mentions on the invoice and the check before invoicing.
- BELGIUMBelgian enterprise number: format and how to check it10 digits starting with 0 or 1, the link with Belgian VAT, establishment units and how to check it.
- SWITZERLANDSwiss UID (CHE) number and Swiss VAT numberThe CHE-123.456.789 format, the TVA, MWST or IVA suffix, VAT groups and how to check a Swiss company.
- APIIntra-EU VAT Number Verification API in JSONVerify a VAT number in one call: format, company, valid or invalid status. France, Belgium, Switzerland, Norway, Finland, Latvia, Sweden, Estonia, Lithuania. Fixed pricing.
03 / COUNTRIES
United Kingdom and Nordic countries
The company number format in the United Kingdom, Norway, Finland, Latvia, Australia, Singapore and Japan, and how to check it.
- UNITED KINGDOMUK company number: format and how to check it8 characters, a prefix for some entity types, leading zeros restored and how to check a British company.
- NORWAYNorwegian organisation number: format and how to check it9 digits and a modulo-11 check, the MVA suffix of Norwegian VAT, establishments and how to check a company.
- FINLANDFinnish Business ID (Y-tunnus): format and how to check it7 digits, a hyphen and a modulo-11 check digit, Finnish VAT and how to check a company.
- LATVIALatvian registration number: format and how to check it11 digits with no published check digit, Latvian VAT and why you need to look the company up to check.
04 / INVOICING AND MONITORING
Invoice, verify and monitor your partners
The new invoicing rules, how to verify a company and the signals to watch for among your customers and suppliers.
- E-INVOICINGFrance e-invoicing 2026: why your customers' SIREN becomes mandatoryThe four new mandatory mentions, the 2026-2027 timeline and how to verify your customers' SIREN numbers.
- VERIFICATIONIs this company real? Checks before signingA six-point checklist: identifier, status, name and address, VAT, signals and sanctions lists.
- STATUSStruck-off, closed or dormant French company: how to tellStruck off, closed, dormant: the definitions, why to check before invoicing and how to be alerted to a change.
- INSOLVENCY PROCEEDINGSHow to check if a French company is in liquidationLiquidation, redressement and sauvegarde explained, the signals to watch and alerts on your customers and suppliers.
- E-INVOICINGCustomer file: the errors that get an e-invoice rejectedMissing SIREN, a zero lost in a spreadsheet, a SIRET mistaken for a SIREN, a closed company, a duplicate: how to recognise them.
- MONITORINGAutomatically monitor your customers and suppliersClosure, insolvency proceedings, name or address change: get told by e-mail or webhook without rechecking.
- CUSTOMSEORI number: what it is for and how to check itThe customs identifier of companies that import or export: what it is for, the link with the SIRET and how to check it.
- CUSTOMER FILEClean Your Customer File for E-InvoicingCheck SIRENs, spot closed companies and duplicates before e-invoicing: a 7-step method, free diagnostic, corrected file from €29 excl. VAT.
05 / CHOOSING A TOOL
Choosing an API
Concrete criteria to compare company data services before you commit.
- COMPAREHow to choose a company data API: 8 criteriaCoverage, validation, up-to-date data, SLA, pricing, documentation, GDPR and monitoring: the grid to compare.
- PRICINGCompany data API: credits or flat price, how to work out the costThe formula for the cost of a credit-based API, the questions to ask and the case where each model wins.
- TUTORIALAdd company autocomplete to a formSuggest companies from the first letters: cURL call, server-side relay, JavaScript code and validation.
- COMPAREHow to Choose a Company Data API: Comparison GuideCoverage, fixed price or credits, data freshness, webhooks and documentation: the five key criteria for choosing a company data API in 2026.
- COMPAREPappers API Alternative: Fixed Plan, No CreditsCompare the pricing models of company data APIs: credits or a fixed plan. When to choose each one, with sources and date.
- APISIREN and SIRET API: Search, Autocomplete, ValidationSIREN and SIRET API in JSON: company record, search by name, autocomplete and number validation. Discovery plan (free), then fixed pricing with no credits.