What goes on an invoice and why it matters

An invoice is a written request for payment that documents what you sold or what work you did, how much it costs, and when you expect to be paid. It serves as a record for both you and the person paying you—it proves the debt exists, shows what the money is for, and creates a paper trail if payment goes wrong or a dispute arises later.

An invoice is not the same as a receipt. A receipt proves payment already happened. An invoice requests payment that has not yet arrived. If you are waiting for money, you send an invoice. If you have already received it, you send a receipt.

You need an invoice whenever someone owes you money for goods or services and you want a formal record of the transaction. This includes freelance work, small business sales, repairs, consulting, or any arrangement where payment is not immediate.

Key Takeaways

  • An invoice must include your name and contact information, the customer's name and address, an invoice number, the date issued, a description of what was sold or done, the amount owed, and the payment due date.
  • Payment terms—such as "due upon receipt" or "net 30"—tell the customer when you expect the money and should be stated clearly on the invoice.
  • You can create an invoice using a template in Word or Google Docs, accounting software like Wave or QuickBooks, or a simple spreadsheet.
  • Send the invoice by email, mail, or hand delivery, and keep a copy for your records in case you need to follow up on a late payment.
  • If payment does not arrive by the due date, send a reminder email before taking further action.

The required information on every invoice

Your invoice must include your name, address, phone number, and email address so the customer knows who to pay and how to reach you with questions. If you operate under a business name, include that too. If you have a business license number or tax ID, add it—some customers require this for their records.

Next, include the customer's full name and mailing address. This is especially important if you are mailing a paper invoice or if the customer needs to match the invoice to their own records. If you are invoicing a business, use the business name and the address where they want invoices sent, which may differ from their physical location.

Add an invoice number—a unique identifier for this invoice. Start with 001 and increase by one for each invoice you issue. This number helps you track payments, organize your records, and refer to a specific invoice if the customer questions it. Write it clearly at the top of the invoice.

Include the date you issued the invoice and the date payment is due. These are not the same. The issue date is when you send it. The due date is when you expect the money. If you do not specify a due date, the customer may assume they have unlimited time to pay.

Describing what the customer owes you

Write a clear description of what you provided—not vague, but not a novel either. Instead of "work," write "website design consultation, 3 hours at $75/hour" or "plumbing repair: replaced kitchen sink faucet and supply lines." The customer should read this and immediately know what they are paying for.

If you provided multiple items or services, list each one on a separate line with its own cost. This makes the invoice easier to read and helps the customer verify they are being charged correctly. Include the quantity if relevant: "Logo design (1) — $500" or "Lawn mowing, 4 visits in June — $100 per visit."

Add up the subtotal. If you charged tax, show the tax amount separately and then show the final total. If you offered a discount, show the original price, the discount amount, and the new total. Transparency here prevents confusion and disputes.

Setting payment terms and due dates

Payment terms tell the customer when you expect to be paid. Common terms include:

  • Due upon receipt: Payment is expected as soon as the customer receives the invoice, usually within a few days.
  • Net 15: Payment is due 15 days after the invoice date.
  • Net 30: Payment is due 30 days after the invoice date. This is standard for many business-to-business transactions.
  • Net 60: Payment is due 60 days after the invoice date, often used for larger contracts or government work.

Write your payment terms clearly on the invoice. If you have no preference, "due upon receipt" is safest because it sets the earliest expectation. If you are invoicing a business and they typically pay on Net 30 terms, match that expectation or negotiate before sending the invoice.

State how the customer should pay you: cash, check, bank transfer, credit card, PayPal, Venmo, or another method. Include the specific details they need—your mailing address for checks, your bank account information for transfers, or a payment link for digital methods. The easier you make it to pay, the faster you get paid.

Tools and templates for creating invoices

You do not need expensive software to create an invoice. A simple template in Microsoft Word or Google Docs works fine. Search "invoice template" in either program, choose a layout you like, and fill in your information. Save it as a template so you can reuse it for future invoices.

If you invoice regularly, consider free accounting software like Wave or Square Invoices. These tools let you create, send, and track invoices from your phone or computer. They automatically number invoices, remind you of overdue payments, and store everything in one place. Some also accept payments directly through the invoice, which speeds up collection.

A spreadsheet in Excel or Google Sheets also works if you prefer simplicity. Create columns for invoice number, date, customer name, description, amount, and due date. This method is less polished but gives you full control and requires no subscription.

Whatever tool you choose, keep a copy of every invoice you send. Store it in a folder on your computer, in cloud storage like Google Drive, or in your accounting software. You will need these records if a payment is late, if a customer disputes the amount, or if you need to prove income for taxes.

How to send an invoice and follow up on payment

Email is the fastest and most common way to send an invoice. Attach a PDF copy so the formatting does not change when the customer opens it. Write a brief message: "Hi [name], attached is the invoice for [description of work]. Payment is due by [date]. Please let me know if you have any questions." Keep it professional but friendly.

If the customer prefers mail, print the invoice on your letterhead, sign it if you want, and send it via regular mail or certified mail if you need proof of delivery. For large amounts or formal contracts, certified mail shows you made a good-faith effort to deliver it.

If you are meeting the customer in person, hand them a printed copy and keep one for yourself. Ask them to confirm they received it and understand the due date.

If payment does not arrive by the due date, wait a few days and send a polite reminder email. Do not assume they ignored you—invoices get lost, forgotten, or buried in email. Write: "Hi [name], I wanted to follow up on the invoice I sent on [date] for [amount]. Payment was due on [date]. Could you let me know when I can expect it?" Give them a chance to respond before taking further action.

What to do if a customer does not pay

If a customer ignores your reminder, send a second email stating the invoice is now overdue and ask for a specific payment date. Keep your tone professional—you still want to be paid, and hostility makes that less likely. Reference the invoice number and original due date so there is no confusion.

If the customer says they cannot pay on time, ask when they can pay and get that in writing via email. This creates a new agreement and shows good faith on both sides. If they miss that new date, you have documentation of the broken promise.

If the customer refuses to pay or stops responding, you have a few options depending on the amount and your relationship. For small amounts, you may decide the cost of pursuing it is not worth the effort. For larger amounts, you can send a formal demand letter (a template is available online) stating the amount owed and giving them 10 to 30 days to pay before you pursue legal action.

If you still do not get paid, you can file a claim in small claims court if the amount is within your state's limit (usually $5,000 to $25,000). You will need your invoice, any emails about the debt, and proof you attempted to collect. Small claims court is faster and cheaper than hiring a lawyer, and you do not need one to represent you.

Frequently Asked Questions

Can I invoice someone after the work is already done?

Yes. You can invoice at any time—before, during, or after you provide the service. For one-time work, invoicing after completion is normal. For ongoing work, you might invoice weekly or monthly. The invoice date is when you send it, not when the work happened.

What if the customer says they never received my invoice?

Send it again, this time by a different method if possible. If you emailed it, also mail a printed copy or ask them to confirm receipt via email. Keep records of every attempt to deliver it. If you eventually pursue payment, you will need to show you made reasonable efforts to notify them.

Should I include my social security number or tax ID on an invoice?

Only if the customer specifically asks for it or if you are required to by law (for example, if you are a contractor and they need it for tax reporting). Otherwise, leave it off to protect your privacy. Your name and contact information are enough for payment purposes.

What if I need payment before I do the work?

Send an invoice marked "Deposit Due" or "Prepayment Required" with the due date before work begins. Once they pay, you can start. This protects you from doing work for someone who does not pay. Some people call this a deposit invoice or a proforma invoice.

Can I charge interest on a late payment?

You can if you state it on the invoice before sending it. For example: "Late payments subject to 1.5% monthly interest" or "If payment is not received by [date], a $25 late fee will be added." Check your state's laws—some states cap how much interest you can charge. Always disclose the fee upfront so the customer knows what to expect.