Auto-Fill Company Details on Invoices
Never manually type a Dutch company name or address on an invoice again. Enter a KVK number and let the API fill in the rest -- correctly, every time.
Incorrect invoice details waste time and delay payments
Dutch invoicing has strict requirements. Invoices must include the correct legal company name (not a trade name), the registered business address, and a valid VAT (BTW) number. Get any of these wrong and the invoice may be rejected, delayed, or flagged during an audit.
For international invoicing platforms serving Dutch customers, this is a persistent source of errors. Users type company names with typos, use outdated addresses, or enter VAT numbers in the wrong format. Your support team ends up fielding tickets about rejected invoices and incorrect company details.
The Dutch tax authority (Belastingdienst) requires that invoices for B2B transactions include a valid BTW number. If the number is incorrect or unvalidated, the invoice is not tax-compliant. This creates risk for both the sender and recipient.
Prefill invoices with verified company data
The KVKBase API lets your users enter a KVK number and instantly populate all company fields on an invoice. The legal company name, registered address, postal code, city, and validated VAT number are all returned in a single API call, formatted and ready for your invoice template.
async function prefillInvoice(kvkNumber) {
const resp = await fetch(
`https://api.kvkbase.nl/v1/lookup/${kvkNumber}`,
{ headers: { "Authorization": `Bearer ${API_KEY}` } }
);
const company = await resp.json();
return {
invoice_to: company.naam,
address_line_1: company.adres.straat,
postal_code: company.adres.postcode,
city: company.adres.plaats,
country: "Netherlands",
vat_number: company.btw_nummer,
vat_valid: company.btw_geldig,
kvk_number: company.kvk_nummer,
};
}
// User enters KVK number, invoice fills automatically
const invoiceData = await prefillInvoice("12345678");The API returns the legal company name as registered with the KVK, not trade names or abbreviations. This ensures your invoices always use the correct legal entity name -- a common requirement for Dutch B2B invoicing and tax compliance.
VAT validation is included in every response. The btw_geldig field confirms whether the VAT number is currently valid according to VIES, and the validation timestamp provides an audit trail for your records.
Why invoicing platforms choose KVKBase
Tax-compliant invoices
Every invoice uses the correct legal name, registered address, and validated VAT number. Compliant with Dutch Belastingdienst requirements from the start.
Zero manual data entry
Users enter a single KVK number. Company name, address, and VAT number fill in automatically. No more typing, no more typos.
Fewer rejected invoices
Incorrect company details are the top reason invoices get rejected. With verified data from the KVK registry, rejections drop to near zero.
Fast integration
A single REST API call returns everything you need. JSON response maps directly to invoice fields. Most teams integrate in under an hour.
Three steps to perfect Dutch invoices
User enters KVK number
When creating a new invoice or adding a Dutch client, the user types the 8-digit KVK number into your form.
API returns company data
KVKBase looks up the company and returns the legal name, registered address, VAT number with validation status, and legal form.
Invoice is prefilled
Your app maps the data to invoice fields. The user reviews, confirms, and sends a perfectly formatted, tax-compliant invoice.
Make every Dutch invoice accurate
Start with 100 free lookups per month. No credit card required. Integrate with your invoicing app in minutes.
Get started free