The Sole Proprietorship Invoice is a fundamental business document used by independent entrepreneurs (ZZP'ers) in the Netherlands to bill clients for goods or services provided. This document type must comply with strict requirements set forth by Dutch tax authorities (Belastingdienst) and commercial law, including mandatory elements such as VAT calculations, KVK number, and specific payment terms. It's particularly important for maintaining proper business administration and tax compliance in the Dutch market, where sole proprietorships represent a significant portion of business activities. The invoice serves multiple purposes: as a payment request, a tax document for VAT returns, and legal proof of business transactions. When operating in the Netherlands, sole proprietors must ensure their invoices meet all local regulatory requirements while maintaining professional standards expected in their respective industries.

1. Invoice Header: Company logo, 'INVOICE' title, and invoice number

2. Seller Details: Business name, address, KVK number, VAT number, bank details, contact information

3. Buyer Details: Client's name, company (if applicable), address, and VAT number (if applicable)

4. Invoice Information: Invoice date, due date, reference number, purchase order number (if applicable)

5. Service/Product Details: Itemized list of services/products, quantities, unit prices, and descriptions

6. Calculation: Subtotal, VAT calculation, and total amount due

7. Payment Terms: Payment deadline, accepted payment methods, bank account details

8. Footer: Legal requirements including KVK number, VAT number, and applicable terms