Why use an online invoice generator?
As a business owner, freelancer, or online store operator, invoicing is an essential part of your operations. But why choose online invoice generation over traditional methods?
Benefits of online invoicing:
• Time savings: No more manual typing, automatic calculations
• Professional appearance: Consistent, neat invoices
• Fewer errors: VAT is calculated automatically
• Always accessible: Work from any location with internet
• Free to use: Many tools are completely free
• Legally compliant: Automatic verification of required fields
With our free invoice generator, you can create a professional invoice in minutes that complies with all legal requirements.
Required information on an invoice
An invoice must contain certain information according to law. If information is missing, tax authorities may reject the invoice and VAT cannot be reclaimed.
Legally required invoice information:
• Invoice number: Unique and sequential number
• Invoice date: Date of issue
• Seller details: Name, address, city
• VAT number: Your VAT identification number
• Business registration: Company registration number
• Buyer details: Customer name and address
• Description: Clear description of products/services
• Quantity and price: Specification per line
• VAT rate: Applicable rate per line
• VAT amount: Total VAT separately stated
• Total amount: Including and excluding VAT
Our invoice maker automatically ensures all required fields are present.
Step-by-step: Creating an online invoice
With our free tool, you can create a professional invoice in 5 simple steps:
Step 1: Enter your business details
Enter your company name, address, VAT number, and IBAN. These details can be saved for future invoices.
Step 2: Add customer details
Enter your customer's name and address. For business customers, also include the VAT number.
Step 3: Add invoice lines
Describe your products or services, add quantities and prices. Select the correct VAT rate per line.
Step 4: Review the preview
Check how your invoice looks before downloading. Verify all information is correct.
Step 5: Download or send
Download your invoice as PDF or export to UBL format for your accounting.
VAT calculation on your invoice
One of the most common invoicing mistakes is incorrect VAT calculation. Our tools do this automatically, but it's good to understand how it works.
Understanding VAT rates:
Different countries have different VAT rates. Make sure to apply the correct rate for your jurisdiction and type of goods/services.
VAT calculation:
Price excluding VAT × VAT percentage = VAT amount
Example: €100 × 21% = €21 VAT → Total €121
Use our free VAT calculator for quick calculations.
When not to charge VAT:
• Reverse charge mechanism for B2B within EU
• Export outside the EU
• Small business exemption (varies by country)
UBL invoices: The digital standard
UBL (Universal Business Language) is the international standard for electronic invoices. More and more businesses and governments only accept UBL invoices.
Benefits of UBL invoices:
• Automatic processing: Accounting software can read UBL directly
• Fewer errors: No more typing mistakes
• Required for government: Many government entities require UBL
• Future-proof: E-invoicing is becoming the norm
With our tools, you can easily work with UBL invoices:
• Invoice Creator - Generate invoices and export to UBL
• PDF to UBL Converter - Convert existing PDF invoices to UBL
• UBL to PDF Converter - Create readable PDFs from UBL files
• UBL Validator - Check if your UBL file is valid
IBAN validation: Prevent payment problems
A common problem with invoicing is an incorrect IBAN number. This leads to failed payments and delays.
Why validate IBAN?
• Prevent typing errors in bank account numbers
• Verify the IBAN format is correct
• Identify the bank and country of the account
• Prevent payment problems and delays
Use our free IBAN validator to check IBAN numbers before putting them on invoices.
What does the IBAN validator check?
• Correct length per country
• Valid country code
• Valid check digit
• Bank identification (BIC/SWIFT)
Tips for professional invoices
Beyond legal requirements, here are more tips to make your invoices professional:
1. Consistent formatting
Use the same layout for all your invoices. This looks professional and is recognizable to clients.
2. Clear payment terms
State when the invoice should be paid (e.g., 'Due within 14 days'). This prevents disputes.
3. Payment instructions
Make it easy by including your IBAN and possibly a payment link.
4. Professional descriptions
Write clear, specific descriptions. Not 'Services' but 'Website maintenance January 2025'.
5. Add your logo
A logo makes your invoice recognizable and professional.
6. Archive properly
Keep invoices for the legally required period (typically 7 years).
Frequently asked questions
Is a digital invoice legally valid?
Yes, digital invoices are fully legally valid. They must meet the same requirements as paper invoices.
Do I need an invoice number?
Yes, each invoice number must be unique and preferably sequential. Our tool automatically generates unique numbers.
Can I modify an invoice after sending?
No, a sent invoice should not be modified. For errors, create a credit note with our credit note generator.
How long should I keep invoices?
Typically a minimum of 7 years. Digital invoices can be stored digitally.
Must VAT always be on the invoice?
Yes, unless you're exempt or the reverse charge mechanism applies. In such cases, state the reason for exemption.
Free tools summary
Winkel Factuur offers various free tools to support your invoicing process:
📝 Invoice Creator
Create professional invoices with automatic VAT calculation. Export to PDF and UBL.
📄 Credit Note Creator
Create credit notes for returns or corrections.
🔢 VAT Calculator
Quickly calculate VAT amounts with different rates.
🏦 IBAN Validator
Check IBAN numbers for validity.
📤 PDF to UBL Converter
Convert PDF invoices to UBL format.
📥 UBL to PDF Converter
Create readable PDFs from UBL files.
All our tools are free to use and require no registration.