What goes on an invoice
An invoice is a record of what you sold or the work you did, how much it costs, and when payment is due. It is not a request—it is a bill. The person or business receiving it knows they owe you money and has a document to process the payment through their accounting system.
Every invoice needs: your name and contact information at the top; a unique invoice number; the date you issued it; the customer's name and address; an itemized list of what you provided (products, hours, services); the price of each item; the total amount due; and the date payment is due. If you are a business, include your business name, tax ID if you have one, and payment instructions—where and how they should send the money.
The invoice number matters because it lets both you and the customer track the payment. Start with 001 and go up. If you skip numbers or use the same number twice, it creates confusion in their accounting department and delays payment.
Key Takeaways
- An invoice must include your contact details, a unique number, the customer's name and address, an itemized list of what you provided, the total due, and the due date.
- Payment instructions—your bank account, mailing address, or payment app—must be clear and straightforward to find on the invoice.
- The due date is typically 15, 30, or 60 days from the invoice date, depending on your agreement with the customer.
- Itemizing each product or service separately, rather than lumping everything into one line, makes the invoice easier for the customer to verify and process.
How to structure the itemized section
The itemized section is where you list what the customer is paying for. Each line should have a description, a quantity, a unit price, and a line total. For example: "Website design consultation, 3 hours, $75 per hour, $225 total." This is clearer than "consulting services, $225."
If you are selling products, list the product name, how many units, the price per unit, and the total. If you are billing for time, show the number of hours and your hourly rate. If you have multiple services or products, give each one its own line. At the bottom, add up all the line totals to get the subtotal, then explore any taxes or discounts, and show the final amount due.
Customers with accounting departments need this detail because they have to match your invoice to their purchase order or their internal records. A vague invoice slows down payment because someone has to contact you to ask what the charges are for.
Setting the due date and payment terms
The due date tells the customer when you expect to be paid. Common terms are net 15 (payment due 15 days after the invoice date), net 30, or net 60. If you have not agreed on terms with the customer, net 30 is the standard in most industries.
Write the due date as a specific calendar date, not just "30 days"—for example, "Due: January 15, 2025" instead of "Due: 30 days from invoice date." This removes any confusion about when the clock starts.
If you need the money faster, you can offer a small discount for early payment—for example, "2% discount if paid within 10 days." This is called an early payment discount and can speed up cash flow. Write it clearly: "2/10 net 30" means 2 percent off if paid in 10 days, otherwise full payment due in 30 days.
Payment instructions and contact details
Tell the customer exactly how to pay you. If you accept bank transfers, provide your bank account number and routing number, or a payment app like PayPal or Venmo. If you want a check, give your mailing address. If you use an online invoicing tool that accepts credit card payments, include that link.
Put your contact information—phone number and email—at the top of the invoice so the customer can reach you if they have questions. If you are a business, include your business address and tax ID. The clearer your payment instructions, the faster the money moves.
If you are invoicing a large company, they may have a specific payment process or portal. Ask them before you send the invoice where they want it submitted and whether they need it in a particular format.
What to include if you are a business
If you operate as a registered business, add your business name, business address, and business tax ID (EIN in the United States) to the invoice. This is required for the customer's records and for tax purposes.
If you are a sole proprietor or freelancer working under your own name, you still need your full name and address, but you may not have a separate tax ID. Check your local tax rules—some places require you to register even as a solo operator, and some do not.
If you are invoicing a business that will pay with a company check or bank transfer, they will need your business information to process it through their accounting system. Missing details slow down payment.
Common mistakes that delay payment
The most common mistake is not including payment instructions. The customer knows they owe you money but does not know where to send it, so they have to email you to ask. This adds days to the payment timeline.
The second mistake is using the same invoice number twice or skipping numbers. This confuses the customer's accounting department because they cannot match the invoice to their records. They may set it aside to investigate, which delays processing.
The third is being vague about what you provided. "Consulting" or "services rendered" does not tell the customer what they are paying for. They have to contact you to verify, or they may reject the invoice outright. Always itemize.
The fourth is not stating a due date. If the customer does not know when you expect payment, they may assume it is due whenever they get around to it. A specific due date creates accountability.
Tools and formats for creating invoices
You can create an invoice in a spreadsheet (Excel or Google Sheets), a word processor (Word or Google Docs), or an invoicing tool designed for the job. Invoicing tools like Wave, Square Invoices, FreshBooks, or Zoho Invoice automate numbering, track which invoices have been paid, and let you send reminders.
If you use a spreadsheet or word processor, create a template so you do not have to rebuild the invoice each time. Include all the sections above and save it as a template. When you need to invoice someone, open the template, fill in the details, and save it with the invoice number as the filename.
Send the invoice as a PDF so the formatting does not change when the customer opens it. If you use an invoicing tool, it usually generates a PDF automatically and can email it directly to the customer.
Frequently Asked Questions
What if the customer does not pay by the due date?
Send a polite reminder email a few days after the due date. Include the invoice number, the amount due, and the original due date. If they still do not pay after another week, follow up again. Some customers pay late by accident; others are slow payers. A reminder often gets results without damaging the relationship.
Should I include my social security number on the invoice?
No. If you are a sole proprietor, you do not need to include your SSN on the invoice itself. If the customer needs it for tax reporting (for example, if they are a business paying you as a contractor), they will ask for it separately or on a W-9 form. Never put your SSN on a document you email or mail.
Can I invoice for work I have not finished yet?
Yes, if you have an agreement with the customer. You can invoice for a deposit before you start, for milestone payments as you complete stages of the work, or for the full amount when the work is done. Make clear on the invoice what stage the work is at—for example, "50% deposit for website design project" or "Final invoice upon completion."
What if the customer wants to pay in installments?
You can create multiple invoices for different due dates, or you can create one invoice and note the payment plan on it—for example, "Payment plan: $500 due January 15, $500 due February 15." Be specific about each payment date so there is no confusion.
Do I need to include tax on the invoice?
That depends on your location and what you are selling. Some places require sales tax on products but not services. Some require it on both. Check your local tax rules or ask an accountant. If you are required to collect tax, calculate it and add it to the total. If the customer is tax-exempt, ask them for a tax-exempt certificate before you invoice.