What should a professional invoice include?

A professional invoice should include your business name and contact info, client details, a unique invoice number, issue and due dates, itemized line items with quantities and rates, subtotal, any applicable taxes or discounts, the total amount due, payment terms, and accepted payment methods.

How do I calculate sales tax on an invoice?

Apply your local tax rate as a percentage to the subtotal after any discounts. For example, if your subtotal is $1,000 and you have a 10% discount ($100), the taxable amount is $900. At an 8% tax rate, the tax would be $72. Some regions require multiple tax lines (e.g., state + county).

What is Net 30 on an invoice?

Net 30 means the full payment is due within 30 days of the invoice date. Other common terms include Net 15, Net 45, Net 60, and Due on Receipt. The term you choose depends on your industry norms and cash flow needs.

Can I create invoices without software?

Yes. Browser-based invoice generators like the one at Ultimate Design Tools let you create, customize, and download professional PDF invoices without installing any software. Everything runs locally in your browser with no signup required.

UtilityApril 2026·10 min read

How to Create Professional Invoices for Free

Whether you are a freelancer billing your first client or a small business owner managing dozens of accounts, invoicing is the bridge between doing the work and getting paid. This guide covers everything you need to know about creating professional invoices — from what to include, to templates, calculations, and exporting to PDF.

📋

Try the Invoice Generator

Free • No signup • PDF export

In This Guide

What Every Invoice Should Include
Choosing the Right Template
Writing Effective Line Items
Tax, Discounts, and Shipping
Payment Terms That Get You Paid Faster
Branding Your Invoice
Handling Partial Payments
Exporting and Sending
Common Invoicing Mistakes
FAQ

⚡ Key Takeaways

Learn how to create professional invoices for free using our browser-based Invoice Generator.
Covers 1. what every invoice should include.
Covers 2. choosing the right template.
Covers 3. writing effective line items.
Covers 4. tax, discounts, and shipping.

1. What Every Invoice Should Include

An invoice is a legal document requesting payment for goods or services. To be complete and enforceable, it needs specific elements.

Required Elements

Your business information: Company name, address, email, phone, and optionally your tax ID or EIN.
Client information: The name, company, and address of the person or entity being billed.
Invoice number: A unique identifier for tracking. Sequential numbering (INV-0001, INV-0002) is the simplest approach.
Dates: The date the invoice was issued and the date payment is due.
Line items: Each product or service with a description, quantity, unit rate, and line total.
Totals: Subtotal, taxes, discounts, and the final amount due.
Payment terms: When and how you expect to be paid.

Pro tip: Include a PO (Purchase Order) number if your client provided one. Large companies often require this to match invoices to approved purchases.

2. Choosing the Right Template

The template you choose affects how professional your invoice looks. Our Invoice Generator includes four templates, each designed for different contexts.

💡 Tip

Always include -webkit-backdrop-filter alongside backdrop-filter for Safari support. Without the prefix, the effect is invisible to roughly 25% of mobile users.

Modern: A clean layout with a colored sidebar accent. Great for creative agencies, tech companies, and consultants.
Classic: A traditional business layout with centered header and double-rule borders. Ideal for law firms, accounting, and professional services.
Minimal: Ultra-clean with generous whitespace. Works well for designers, architects, and anyone who values simplicity.
Bold: A vibrant colored header with strong typography. Best for marketing agencies, event companies, and brands with strong visual identities.

Each template supports a custom accent color, so you can match it to your brand palette. The default is a warm orange (#FF8A50), but you can change it to any hex value.

3. Writing Effective Line Items

Line items are the heart of your invoice. Each one should clearly describe what was delivered so the client knows exactly what they are paying for.

⚠ Warning

On iOS Safari, backdrop-filter inside a position: fixed element can cause severe scroll performance issues. Test thoroughly on real iOS devices.

Best Practices

Be specific. Instead of "Consulting," write "Brand strategy consultation — 3-hour workshop."
Use consistent units. If billing hourly, show hours as the quantity and hourly rate as the rate.
Group related work. If you did 12 hours of development across three features, you can list each feature separately or group them.
Include dates or references. Adding a date range ("March 1–15") helps clients match invoices to work periods.

Pro tip: Use the Clone button to duplicate a line item and modify it — this saves time when billing for similar work.

4. Tax, Discounts, and Shipping

Our Invoice Generator calculates totals automatically as you fill in the fields. Here is how the math works:

Subtotal = sum of (quantity × rate) for each line item
After Discount = Subtotal - Discount
Tax = After Discount × Tax Rate
Total = After Discount + Tax + Tax 2 + Shipping

You can set discounts as a percentage or a flat amount. For jurisdictions that require multiple tax lines (like state + county in the US, or GST + PST in Canada), use the Second Tax field with its own label and rate.

5. Payment Terms That Get You Paid Faster

Payment terms set expectations. The most common terms are Net 30 (due within 30 days), but shorter terms generally mean faster payment.

Due on Receipt: Payment is expected immediately. Best for small jobs or new clients.
Net 15: A good middle ground. Gives the client two weeks.
Net 30: Industry standard for most B2B work.
Net 60 / Net 90: Common for enterprise clients and government contracts.

Pro tip: When you select a payment term in the Invoice Generator, the due date is automatically calculated from the invoice date. Choose "Custom" if you need a specific date.

6. Branding Your Invoice

A branded invoice reinforces your professionalism. Adding your logo, using your brand colors, and including your website URL all contribute to a polished impression.

Upload your logo (PNG, JPG, or SVG, up to 2MB) using the Logo section. The image is processed entirely in your browser and never uploaded to any server. You can also use the Watermark field to overlay text like "PAID" or "DRAFT" diagonally across the invoice.

7. Handling Partial Payments

Not every invoice gets paid in full at once. The Partial Payments section lets you record each payment as it comes in, with a date, amount, and optional note. The invoice automatically calculates and displays the remaining balance due, and the status badge updates to reflect the current state.

8. Exporting and Sending

When your invoice is ready, click Download PDF to generate a high-quality A4 PDF file. The tool uses html2canvas and jsPDF to render the invoice exactly as it appears in the live preview.

The resulting PDF is a standard file you can attach to an email, upload to a client portal, or print. Your invoice data is also saved locally in your browser, so you can return to it later and make changes.

Pro tip: Use the Save button to store invoices in your local history. You can load, duplicate, or delete past invoices from the History tab.

9. Common Invoicing Mistakes

Missing invoice numbers: Without unique IDs, tracking becomes impossible. Always use sequential numbering.
Vague line items: Descriptions like "Services" invite questions and delays. Be specific about what was delivered.
No due date: If you do not specify when payment is due, do not be surprised when it is late.
Wrong tax rate: Verify your local tax requirements. The wrong rate can create legal issues.
No payment instructions: Tell your client exactly how to pay. Include bank details, PayPal, or Venmo information.

10. Frequently Asked Questions

Is this invoice generator free?

Yes, completely free with no limits, no watermarks, and no signup. The tool runs entirely in your browser.

Is my data private?

All data stays on your device. Nothing is uploaded to any server. Clearing your browser data will erase saved invoices.

Can I use this for international invoicing?

Yes. The tool supports 26+ currencies with correct symbols and decimal formatting. You can also customize tax labels for any jurisdiction.

What file format is the exported invoice?

The export is a standard PDF file in A4 format, rendered at 2x resolution for sharp printing.

Ready to Create Your Invoice?

Free. No signup. Runs 100% in your browser.

Open Invoice Generator →

✍️

Derek Giordano

Founder, Ultimate Design Tools

📚 References & Further Reading

⚡ Try the free Receipt Generator →