To write an invoice, put “Invoice” and your business details at the top, add the client’s billing details, and give it a unique number and date. List each product or service with its price, add tax where it applies, subtract anything already paid, and state the due date and how to pay.
That is the whole job in eight steps, and none of them needs accounting software. Below, each step is shown on a real invoice from start to finish: a freelance web developer billing a bike shop for a website. Every amount comes from our invoice generator.
Put “Invoice” and your business details at the top
Title the document INVOICE in large type, so nobody mistakes it for a quote or a receipt. Under it, write your business name exactly as you want payments made out, then your address, email and phone number.
If you trade under a different name from your own, use the name on your bank account or add both. A license number goes here too if your trade has to show one on paperwork. A logo is optional; clients pay invoices without them every day.
Add who is paying, and their purchase order
Write “Bill to” and the client’s legal or business name, then their billing address. For a company, add the person or department that pays bills, often “Accounts payable”. The person who hired you is not always the person who pays you.
Ask a business client before you invoice whether they use purchase order numbers. If they gave you one, put it on the invoice. Many accounts payable teams match invoices to orders and will set aside one without its PO number.
Give it an invoice number and a date
Every invoice needs a number that is never used twice, so you and the client can both point to it. A simple running sequence works, and adding the year helps sort them later. The invoice date is the day you issue it, which is also when payment terms start counting.
Keep numbering even when an invoice is cancelled: mark it void rather than reusing its number. How to number invoices has formats and a register you can copy.
List each product or service on its own line
Write one line per item with a short description, the quantity, the unit, the price per unit and the line amount. Describe the work in words the client’s bookkeeper will recognize, and add a second line for dates, scope or a proposal reference if it helps.
Fixed-price work goes on as one job at the agreed price. Hourly work shows the hours and the rate. Costs you are passing through, such as a domain renewal or materials bought for the client, belong on their own line, ideally marked “at cost” with the receipt attached.
Add sales tax only where it applies
Sales tax is set by each state, and sometimes by city and county too. Goods are taxed in most states; services vary widely, and some states tax none of them. Mark each line taxable or not, then apply your rate to the taxable lines only.
Our example has no tax line at all, because Oregon has no general sales tax. Check your own state’s rules before you copy anyone else’s invoice. If you do charge tax, show the rate and the amount separately from the price.
Total it and subtract anything already paid
Add the lines to get the subtotal. Take off any agreed discount, add tax and any shipping, and you have the invoice total. Then subtract deposits, retainers or part payments the client has already made.
What is left is the balance due, and it should be the largest, clearest number on the page. A client who sees only the total may pay the deposit twice; showing the payment as its own line prevents that.
State the terms, the due date and how to pay
Payment terms say when the money is due. “Due on receipt” and “Net 15” or “Net 30”, meaning 15 or 30 days after the invoice date, are the most common. Write the actual due date as well, so nobody has to count days. What Net 30 means explains the usual terms.
Then say exactly how to pay: who a check is made out to, whether you take bank transfers or cards, and that the invoice number should go on the payment. If your contract charges a late fee, say so here; do not add one you never agreed.
Send it as a PDF and keep a copy
Save the invoice as a PDF with the invoice number in the file name, and email it to the billing contact, copying the person who hired you. A PDF cannot be edited by accident and looks the same on every screen. Note the date you sent it.
Keep a copy with the deposit record and, later, the payment. The IRS lists invoices among the records that support a business’s income. It generally expects records to be kept for 3 years after you file, or 6 years if income was badly understated.
The finished invoice, step by step
Here are the eight steps on one page. An invented web developer in Portland, Oregon, Lena Ortiz Web Studio, bills Willamette Bike Repair for a website redesign, extra page templates and a domain renewal, and takes off the deposit paid when the work began.
| Step | On this invoice |
|---|---|
| 1 The word INVOICE and your details | Lena Ortiz Web Studio 2214 SE Division Street Portland, OR 97202 lena@example.com (503) 555-0136 |
| 2 Who pays | Willamette Bike Repair Attn: Accounts payable 815 N Mississippi Avenue Portland, OR 97227 |
| 3 Number, date and PO | INV-2026-014, dated 10/16/2026, PO WBR-0412 |
| 4 Line items | Website redesign, fixed fee: 1 job x $2,400.00 = $2,400.00 Extra page templates: 6 hr x $85.00 = $510.00 Domain renewal, at cost: 1 ea x $22.00 = $22.00 |
| 5 Tax | None: Oregon has no general sales tax |
| 6 Totals | Subtotal $2,932.00 Payments received -$800.00 Balance due $2,132.00 |
| 7 Terms and how to pay | Net 15, due 10/31/2026 Bank transfer (ACH) to the account on file, or check payable to Lena Ortiz Web Studio. Please quote the invoice number. |
| 8 Send and record | PDF named INV-2026-014, emailed to accounts payable; copy kept with the deposit record |
The client’s accounts payable team needs nothing beyond this page to pay it: who is owed, for what, how much is left after the deposit, the due date, and where the money goes. The PO number lets them match it to their order on the first try.
If you would rather fill in the boxes than lay out a page, the invoice generator does the arithmetic and makes the PDF. The short video below shows the same steps on screen.
Mistakes that slow down payment
- No due date, only “Net 30”. Write the date too.
- A missing PO number on an invoice to a company that issued one.
- The wrong payee name, one that does not match your bank account.
- A deposit left off, so the balance looks larger than it is and the client queries it.
- Vague lines such as “services”, which the client’s bookkeeper cannot match to anything.
- A reused number, which makes two invoices impossible to tell apart.
Once paid, you can confirm it with a receipt; invoice vs receipt shows how the two documents relate. For more on what an invoice is and the types businesses use, see what is an invoice.
Sources: IRS, What kind of records should I keep and How long should I keep records; Oregon Department of Revenue, Sales tax in Oregon. Checked October 24, 2026.
