The short version
Put on the invoice whatever a client's bookkeeper needs to pay it without calling you: who it is from, who it is for, a number, two dates, the work in lines, the total and how to pay. Add tax only if you are required to charge it. Everything past that depends on the client and the job.
The checklist
The groups come from how invoices get paid, not from a legal list. The next section covers what the law asks for.
Essential
A client's payables team stalls without these.
| Field | What it does |
|---|---|
| Your business name and contact details | Tells the client who to pay and who to call about the invoice. |
| Client name and company | Lets their bookkeeper file the invoice under the right account. |
| Invoice number | One unique number per invoice, so a payment and a question can both point to it. |
| Invoice date | Starts the clock for the payment terms. |
| Due date or payment terms | A date such as November 17, 2026, or terms such as net 14 the client can count from. |
| Itemized lines | A description, quantity, rate and amount for each item or service. |
| Subtotal and total due | The one number the client pays. |
| How to pay | Bank details, a payment link or a check address. |
Only if it applies
Add these when the job calls for them.
| Field | What it does |
|---|---|
| Sales tax | A tax line with the rate and the amount, if you are required to charge tax. |
| Discount or deposit already paid | Shown as lines that bring the total down. |
| PO number | Some clients cannot pay an invoice that does not carry their purchase order number. |
Helpful
Nice to have, never what stops a payment.
| Field | What it does |
|---|---|
| Project or job name | Helps the client match the invoice to the work. |
| Late fee wording | Works only if it was agreed before the work, in the quote or contract. |
| A short note | Thanks, a warranty line, or where to send questions. |
Is any of this required by law?
For an ordinary US business invoice we found no federal form or field list. The IRS says you can use any record-keeping system that clearly shows your income and expenses, and that except in a few cases the law does not require any special kind of records. Invoices are the paperwork behind those records, so keep a copy of every one you send.
Sales tax is the exception that changes the invoice. States set their own rules and differ on which goods and services are taxable. The Texas Comptroller's sales tax page, for example, says the tax applies to most goods and to taxable services, and leaves you to check which services those are. If you charge tax, show it as its own line with the rate. If you are not sure whether your work is taxable, ask your state tax agency before you send the first invoice.
We did not read every state's rules, rules for regulated trades, government contracts or other countries. Outside the US, tax invoices have their own required fields; the VAT number entry is a starting point.
An invoice filled in, line by line
A made-up plumber, Harbor Line Plumbing, bills a client for a repair. Invoice INV-2026-0107 is dated November 3, 2026, on net 14 terms, so the due date is November 17, 2026. Payment is by bank transfer or check. The lines add up like this.
| Line | Working | Amount |
|---|---|---|
| Labor | 4 hours at $125.00 | $500.00 |
| Materials | 1 at $200.00 | $200.00 |
| Sales tax, 8% on materials only (example rate) | 8% of $200.00 | $16.00 |
| Total due | 500 + 200 + 16 | $716.00 |
Labor is 4 x $125.00, which is $500.00. Materials are $200.00. Tax at an example rate of 8% on the materials only is $16.00, because this made-up state does not tax the labor. The total is $500.00 + $200.00 + $16.00, which is $716.00. Your state and your rate will differ, so treat the tax line as an illustration.
The same invoice with a $200.00 deposit already paid would show the deposit as a line below the total and a balance due of $516.00. See the deposit entry for how to word it.
How to fill one in, in order
- Put your business name, address, phone and email at the top, with a logo if you have one.
- Add the client's name and company, and an address or email for their payables team.
- Give the invoice a unique invoice number and the date you issue it.
- Write the due date, or terms like net 30 the client can count from.
- List the work, one line item each, with quantity, rate and amount.
- Add tax as its own line if you charge it, subtract any deposit, and show the total due.
- Say how to pay, then send a PDF or a link and keep a copy.
Mistakes that slow a payment
- No due date. The client picks one, and it is later than yours.
- One lump line, such as "Services, $4,000". An itemized invoice is easier to approve and harder to dispute.
- A total that does not match the lines, usually after a late edit. Add it up once more before you send.
- No PO number when the client's company needs one.
- Reusing an invoice number, which gets the second invoice rejected as a duplicate.
- No way to pay. A link, a bank detail or a mailing address belongs on the page.
Add more for your trade
A roofer lists squares and disposal, a photographer lists a usage license, and a consultant lists hours by task. The invoice items by profession page has example lines for 46 trades, and the trade invoicing guides go through the billing habits of each one.
Once the invoice is paid, the client gets a receipt. The invoice vs receipt page shows how the two documents differ.
Sources
Common questions
What are the basic parts of an invoice?
Your business name and contact details, the client's name, an invoice number, the invoice date, a due date or payment terms, one line for each item or service with quantity, rate and amount, the total, any tax, and how to pay. Everything else is optional.
Is an invoice number required?
We found no federal rule that requires one on an ordinary US invoice. You still want one: a client's payables team uses it to match a payment, and you use it to find the invoice later. Number every invoice once and never reuse a number. Some countries require unbroken sequences, so check the rules where your client is.
Do I have to put sales tax on an invoice?
Only if you are required to charge it. That depends on your state and on what you sold, because states differ on which goods and services are taxable. If you charge tax, show the rate and the amount as their own line. Your state tax agency has the rules, and the sales tax calculator on this site helps with the arithmetic.
Should an invoice show payment terms?
Yes. Write the due date, or terms such as net 30 that the client can turn into a date. An invoice with no due date leaves the client to guess, and a guess is usually later than yours.
What is the difference between an invoice and a receipt?
An invoice asks for payment and a receipt shows that payment arrived. The invoice vs receipt page walks through one job that produces one invoice and two receipts.
Can I make an invoice in Word or Excel?
Yes. The free Word, Excel, PDF and Google Docs invoice templates here have these fields in place. The invoice generator does the addition for you and saves a PDF with no signup.
What this is. A checklist and guide written by InvoiceTools. It is general information, not legal or tax advice, and rules differ by state and country.
Last reviewed by InvoiceTools, Houston, Texas, on 11 November 2026.