How to Create an Invoice in 2026

An invoice is a payment request sent from a seller to a buyer. It documents the goods or services provided, the amounts owed, and the terms of payment. Whether you are a freelancer billing your first client or a small business managing dozens of accounts, the mechanics are the same: accuracy, clarity, and timeliness.

What every invoice needs

At minimum, an invoice must include: your business name and contact details, the client's name and address, a unique invoice number, the issue date, a due date or payment terms, a line-item breakdown of services or products, the total amount due, and accepted payment methods. Many jurisdictions also require your tax ID or VAT number.

Invoice number

Use a sequential numbering system. Common formats include INV-0001, 2026-042, or a prefix per client. The important thing is uniqueness — duplicate numbers cause accounting headaches. Most invoice tools, including iv, auto-generate the next number for you.

Dates and payment terms

The issue date is when the invoice is created. The due date is when payment is expected. Standard terms include Net 15, Net 30, and Net 60 — meaning the client has that many days from the issue date to pay. If you need faster payment, state "Due on receipt" or offer a small discount for early payment (e.g., "2/10 Net 30" means 2% off if paid within 10 days).

Step-by-step: creating an invoice

1. Enter your details

Start with your business name, address, email, and phone number. If you have a logo, include it — it looks professional and helps clients identify you at a glance. In iv, these fields auto-fill from your saved profile after the first invoice.

2. Add the client

Enter the client's legal name and billing address. Use the name that matches their accounting records — "Globex Corporation", not "Bob's company". If the client has a purchase order number, include it on the invoice so their accounts payable team can match it.

3. Add line items

Each line item should have a clear description, quantity, and unit rate. Be specific: "Website development — 5-page marketing site, React, responsive" is better than "Web work". Specificity reduces disputes and speeds up payment.

4. Calculate tax

Tax rules vary by jurisdiction. In the US, sales tax applies to goods in most states but services are taxed inconsistently. In the EU, VAT applies to most transactions. If you are unsure, consult your accountant. Most invoice generators let you set a tax percentage that auto-calculates the amount. In iv, you can set the tax rate per invoice or save a default in your settings.

5. Add discounts and shipping (if applicable)

Discounts can be flat amounts or percentages. Shipping charges are typically added as a separate line or a flat fee below the subtotal. Keep the math transparent — clients should be able to verify the total themselves.

6. Include payment instructions

Tell the client exactly how to pay: bank transfer details, PayPal address, Stripe payment link, or check mailing address. The fewer steps between "invoice received" and "payment sent", the faster you get paid.

7. Review and send

Double-check the math, the client name spelling, and the invoice number. Export as PDF for a permanent record. iv supports 17 professional templates and exports to PDF, DOCX, XLSX, CSV, and JSON.

Common mistakes

• Missing due date. Without a deadline, clients deprioritize payment. Always state when payment is expected.
• Vague line items. "Consulting" tells the client nothing. Describe the deliverable.
• Wrong client name. If the invoice is addressed to the wrong legal entity, accounts payable may reject it.
• No invoice number. Makes it impossible to reference in follow-ups or disputes.
• Forgetting tax. Undercharging tax is your liability, not the client's.

Digital vs. paper invoices

Paper invoices still exist but are declining. The EU's e-invoicing mandate (effective 2028 for cross-border B2B) will require structured electronic invoices in many cases. Digital invoices are easier to search, harder to lose, and faster to process. If you are not already sending invoices electronically, now is the time to switch. Read our EU e-invoicing compliance guide for details.

Tools

You can create invoices in a spreadsheet, a word processor, or a dedicated tool. Spreadsheets work but are error-prone and hard to track. Word processors produce nice-looking documents but lack calculations. Dedicated invoice generators like iv handle numbering, tax math, PDF export, and client management in one place — and iv is free for individuals with no signup required.

If you are comparing options, see our comparison of free invoice generators vs. QuickBooks.

Summary

A good invoice is complete, specific, and sent promptly. Include all required fields, describe your work clearly, and make it easy for the client to pay. The rest is just formatting.