How to Write an Invoice
By the BePaid team · Updated · 4 min read
Short answer
To write an invoice, put your business details and the client's details at the top, add a unique invoice number, the invoice date and a due date, then list each product or service with quantity, rate and line total. Finish with the subtotal, any sales tax, the total due, your payment terms and how the client can pay. Keep descriptions specific so the client can approve it without questions.
Before you start: gather the details
Writing an invoice goes fast when you have everything in one place. Before you open a template or the free invoice generator, pull together:
- The client's legal or business name, contact person, billing address and email.
- What you agreed to: the quote, estimate, contract or email thread that sets the price.
- Dates of the work, hours logged, or materials used.
- Your payment terms (for example, due on receipt or net 30) and the ways you accept payment.
Step-by-step: how to write an invoice
- Add a clear header. Label the document "Invoice" and include your business name, logo if you have one, address, phone and email.
- Add the client's details. Use the name and address their accounts payable team expects. Add a PO number if they gave you one.
- Assign a unique invoice number. Use a simple, sequential scheme so every invoice can be found later. See how to number invoices for options.
- Add the invoice date and due date. The due date should follow from your terms, such as 30 days after the invoice date for net 30.
- List each line item. Give every product or service its own line with a short description, quantity (hours, units, days), rate and line total.
- Calculate totals. Show the subtotal, any discount, sales tax if it applies, deposits already paid, and the final amount due.
- State payment terms and methods. Spell out when payment is due, how to pay (check, bank transfer, payment app) and any late fee you agreed on upfront.
- Add a short note. A thank-you line or a reference to the project helps the invoice feel personal and gives context.
- Review, save as PDF and send. Double-check names, math and dates, then send it as a PDF so the layout can't change.
A worked example
Here's what a small freelance design invoice might look like once everything is filled in:
INVOICE #2026-0042 From: Rivera Design Studio, 120 Main St, Austin, TX 78701, hello@riveradesign.com Bill to: Oakline Coffee Co., Attn: Dana Lee, 45 Elm Ave, Austin, TX 78702 Invoice date: Oct 1, 2026 Due date: Oct 31, 2026 (Net 30) Logo design, 3 concepts + 2 revision rounds — 1 × $1,200.00 = $1,200.00 Menu board layout — 6 hrs × $75.00 = $450.00 Subtotal: $1,650.00 Deposit received: –$400.00 Total due: $1,250.00 Payment: bank transfer or check payable to Rivera Design Studio Note: Thanks for the great project! Final files are in the shared folder.
How to describe your work
Vague line items are one of the most common reasons invoices get held up. "Services" forces the client to ask what they are paying for. "Bathroom demo and haul-away, 2 days" or "Monthly bookkeeping, September 2026" gets approved faster. Match the wording to your quote or contract so the client can check it at a glance.
| Vague | Clear |
|---|---|
| Consulting | Strategy workshop, Sep 12, 4 hrs × $150 |
| Materials | 1/2" PEX pipe, 100 ft × $0.65/ft |
| Photography | Headshot session, 10 edited images |
| Cleaning | Deep clean, 3-bed house, Sep 20 |
Sales tax
Sales tax rules vary by state. Many states don't tax most services, while physical goods and some services are usually taxable. If you charge tax, show it as its own line instead of burying it in the rates. Check your state's rules or talk to a tax professional if you're unsure.
Common mistakes to avoid
- Reusing or skipping invoice numbers, which makes records hard to follow.
- Leaving off the due date. "Pay when you can" rarely gets paid quickly.
- Adding a late fee the client never agreed to. Put late fees in your contract or quote first, and check your state's limits.
- Sending an editable file instead of a PDF.
- Forgetting to record deposits, so the total due looks wrong.
Tools that make it faster
A template keeps every invoice consistent. Browse the invoice templates or start from the simple invoice template. The BePaid invoice generator is free with no signup: you fill in the fields, see a live preview (marked with a "BePaid preview" watermark), and your draft is saved in your browser on that device. To create the clean final PDF, use the BePaid iPhone app, where your first invoice is free. The app doesn't import the web draft, so you'll re-enter the details there. If you work in a specific trade, the invoice generator for freelancers and for contractors show what fields matter most.
Not sure which fields are required? Read what to put on an invoice, then how to send an invoice when it's ready.
Put this into practice
Create an invoice free on the web, then finish it in the BePaid app.
Frequently asked questions
What is the minimum an invoice needs?
Your business name and contact details, the client's name, a unique invoice number, the invoice date, a description of what you're billing for, the amount due, and when and how to pay.
Can I write an invoice in Word or Google Docs?
Yes. Any document works as long as it has the right details and you send it as a PDF. A template or invoice generator just saves time and keeps numbering and math consistent.
Should I include sales tax on my invoice?
Only if what you sell is taxable in your state. Many states don't tax most services. Check your state's rules or ask a tax professional.
How soon after finishing a job should I invoice?
As soon as possible, ideally the same day or within a few days. The payment clock usually starts from the invoice date, so a late invoice means later payment.