Create a PDF invoice as a freelancer — what to include and how to do it

2 min read·25 July 2026

As a freelancer you send invoices to clients. A PDF invoice is professional, easy to archive and universally openable. This guide covers what must legally be on it, how to format it and how to store it correctly.

Legal requirements on an invoice

An invoice must contain at minimum: • Your name and address • Invoice number (unique, sequential) • Date • Client name and address • Description of the service/product • VAT amount (or VAT exemption notice with reason) • Total amount • VAT number (or company registration number) • Payment term and bank account number

Format invoice in Word or Google Docs

Start with an invoice template in Word or Google Docs (available free via Microsoft Office templates or Google Sheets). Adjust name, logo and colours. Export as PDF via "Save As PDF". Remember to increment the invoice number for each new invoice.

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Add logo and signature

An invoice with your company logo looks more professional. Insert the logo as an image in Word or Google Docs. Want to sign it too? Use PDFrust Sign to add a digital signature. Note: invoices do not legally require a signature to be valid — but it builds trust.

Tracking invoice numbers

The invoice number must be unique and sequential — tax authorities expect a consecutive series. Start the year with 001 or a year format like 2026-001. Keep a spreadsheet or use accounting software (like QuickBooks or FreshBooks) that tracks numbering automatically.

Retention: how long and how

Keep invoices for at least 7 years (statutory retention period). Store them as PDFs per year in a folder (2026/Invoices). Use cloud storage as a backup. For formal archiving: convert to PDF/A via PDFrust Archive.