An invoice is more than a request for money. A clear, complete invoice gets paid faster, looks professional, and keeps your records in order for taxes. This guide explains what to include, common mistakes, and how to create a PDF invoice for free.
What to include on an invoice
A complete invoice usually has these parts:
- The word "Invoice" at the top, so it's clearly a bill and not a quote.
- Your business details: business or full name, address, email or phone, and your logo if you have one.
- Your client's details: company or person's name, address and contact.
- Invoice number: a unique number for every invoice (more on this below).
- Invoice date and due date.
- Line items: a description of each product or service, with quantity, price per unit and amount.
- Subtotal, discounts, tax and total: shown separately so the client can see how the total was calculated.
- Payment terms and details: how and when to pay, such as bank details, a payment link or accepted methods.
- Notes: a thank-you message, late payment terms or a reference number.
If you're registered for sales tax, VAT or GST, local rules may require extra details, such as your tax registration number (and the client's), tax rates per item or product codes. Check what your tax authority requires.
How to number your invoices
Every invoice needs a unique number, and numbers should follow a sequence with no gaps or repeats. Simple systems work best:
INV-0001,INV-0002,INV-0003…- With the year:
2026-001,2026-002… - Per client:
ACME-001,ACME-002…
Pick one format and stick to it. A clear numbering system makes it easy to find invoices, track payments and answer questions from your accountant.
Taxes and discounts
- Discount: shown as a percentage, applied before tax, so the client sees the saving.
- Tax: enter the tax rate and name it correctly (for example VAT, GST or sales tax). If you're not registered for tax, don't add it.
- Shipping or other costs: add them as separate lines, so the total is transparent.
Payment terms that get you paid faster
- Set a clear due date. "Due on receipt", "Net 15" (15 days) and "Net 30" are common.
- Make paying easy: include full bank details or a payment link.
- Say what happens if payment is late, if your agreement allows a late fee.
- Send the invoice promptly, right after the work is delivered.
- Follow up politely a few days before and after the due date.
How to make an invoice for free (step by step)
- Open the Invoice Generator.
- Fill in your business details and add your logo.
- Fill in your client's details.
- Enter the invoice number, date and due date.
- Add your items with quantity and price. Totals are calculated automatically.
- Choose your currency, and add tax, discount or shipping if needed.
- Add payment terms and bank details in the notes.
- Click Download PDF and send it to your client.
Your business details are saved in your own browser, so your next invoice takes only a minute. Nothing is uploaded to a server.
Common invoice mistakes
- Missing or duplicate invoice numbers
- No due date, or vague terms like "pay soon"
- Vague descriptions ("services"). Write what you did and for which period.
- Calculation errors (use a generator that totals automatically)
- Wrong client name or address
- Adding tax when you're not registered, or forgetting it when you are
- Sending an editable document instead of a PDF
Frequently asked questions
Is an invoice the same as a receipt? No. An invoice asks for payment. A receipt confirms that payment was received.
Can I make invoices in any currency? Yes. Choose from common currencies like USD, EUR, GBP, INR and more.
Do I need accounting software? Not when you're starting out. A clear PDF invoice and a simple record of what was paid is enough for many freelancers. As you grow, ask an accountant what works for you.
Create your invoice now. It's free, with no watermark and no sign-up.