What goes in an invoice and why it matters
An invoice is a written request for payment that tells the person or business owing you money exactly what they owe, why, and how to pay it. It is not the same as a receipt — a receipt proves payment already happened, while an invoice asks for payment to happen.
A proper invoice protects you because it creates a record. If someone claims they never knew what they owed, or disputes the amount later, your invoice is evidence of what you agreed to. It also makes the other person's job easier — they can show your invoice to their accountant or manager to get the payment approved.
You do not need fancy software or a template to send an invoice. A straightforward email or document with the right information works just fine, especially if you are invoicing someone you know or a small business.
Key Takeaways
- An invoice must include your name and contact details, the other person's name, what you did or sold, the amount owed, and the date you sent it.
- You can send an invoice by email, in person, or by mail — the method depends on who you are billing and how formal the situation is.
- Give the other person a clear important date for payment, usually 15 to 30 days from the date you send the invoice.
- Keep a copy of every invoice you send and note when payment arrives, so you have a record if there is a dispute later.
- If someone does not pay by the important date, send a polite reminder email before taking further action.
The six pieces of information every invoice needs
Your information: Write your full name, address, phone number, and email at the top. If you run a business, include the business name. This tells the person how to reach you and who to make the check out to.
Their information: Write the name of the person or business you are billing, their address, and any account number or reference they gave you. If you are billing a company, try to include the name of the person who hired you or approved the work.
An invoice number: Give your invoice a number — it can be as straightforward as "Invoice 1," "Invoice 2," and so on. This makes it straightforward to track if you send multiple invoices, and it helps the other person's accounting department file it correctly.
The date: Write the date you are sending the invoice. This is the date the payment clock starts — if you say payment is due in 30 days, it is 30 days from this date.
What you did or sold: Describe the work, product, or service clearly. Instead of "consulting," write "three hours of bookkeeping help on March 15." Instead of "supplies," list what supplies and how many. The more specific you are, the less likely someone will question the invoice later.
The amount and payment important date: Write the total amount owed in numbers and words — "Total: $500 (five hundred dollars)" — so there is no confusion. Then write "Payment due by [date]," usually 15 to 30 days from the invoice date. For small jobs or people you know, you can also write "Payment due upon receipt," meaning as soon as they get it.
How to format and send your invoice
The simplest format is a document you can create in Word, Google Docs, or even a text editor. Start with your information at the top, then the other person's information, then a table or list showing what you did and how much it costs. At the bottom, write the total, the due date, and how they should pay you.
If you are billing a business or someone you do not know well, send the invoice as a PDF file attached to an email. This prevents accidental changes and looks more professional. If you are billing a friend or someone local, you can print it and hand it to them, or email it as a regular document.
In your email, keep the message short: "Hi [name], I am sending you an invoice for [brief description of work]. Please let me know if you have any questions." Do not make it sound like a demand — you are just making sure they have what they need to pay you.
If the person prefers to pay in cash or by a specific method, mention that in your email: "You can pay by check, Venmo, or cash — whatever works best for you."
What to do if someone does not pay by the due date
Wait a few days after the due date, then send a friendly reminder. You can email or call: "Hi [name], I wanted to check in — did you receive the invoice I sent on [date]? Let me know if you have any questions or if there is a problem." Many people straightforward forget, and a gentle reminder solves it.
If they still do not respond after a week, send a second message that is a bit more direct: "I have not received payment for invoice [number] dated [date], which was due on [date]. Please let me know when I can expect it." At this point, you are documenting that you have asked multiple times.
If the amount is small and the person is someone you know, you may decide it is not worth the effort to pursue further. If it is a larger amount or a business that is ignoring you, you have other options — small claims court, a collection agency, or a lawyer — but those are separate from the invoicing process itself.
Keeping records of your invoices
Save a copy of every invoice you send, along with a note of when payment arrived. You can keep these in a folder on your computer, a spreadsheet, or even a notebook. The goal is to have proof that you sent the invoice and proof that you received payment.
If you are self-employed or run a business, these records are important for taxes. You need to show the government what money came in and when. Even if you are just doing occasional side work, keeping invoices and payment records makes tax time much simpler.
If you use a payment app like Venmo or PayPal, those apps keep records for you automatically. But if someone pays by check or cash, your invoice and a note of the payment date are your only proof, so do not throw them away.
When to use a template or invoicing software
If you send invoices regularly — more than once a month — it is worth using a template or straightforward invoicing software. Free options like Wave, Square Invoices, or Google Sheets templates let you create an invoice once and reuse it, filling in different names and amounts each time.
These tools also let you track which invoices have been paid and which are still waiting, send automatic reminders, and keep everything organized in one place. But they are not necessary if you only invoice occasionally. A document you create yourself works just fine.
Some invoicing software can accept payment directly through the invoice — the person clicks a button and pays by card. This speeds things up, but it usually costs you a small fee (often 2 to 3 percent of the payment). For small amounts or people you trust, a straightforward invoice and a separate payment method is usually cheaper.
Frequently Asked Questions
Can I send an invoice after the work is already done?
Yes. You can send an invoice at any time, but it is better to send it soon after the work is finished or the product is delivered, while it is fresh in both your minds. If you wait weeks or months, the other person may have forgotten what they owe you for, and they may be less willing to pay.
What if someone says they never got my invoice?
If you emailed it, ask them for their email address again and resend it. If you handed them a printed copy, ask them to confirm they have it. Going forward, if you email an invoice, send it from an email account you check regularly so you can see if they reply with questions. For important invoices, you can also ask them to confirm they received it.
Should I include my tax ID or business license number on the invoice?
If you are self-employed or run a registered business, yes — include your tax ID or business license number if you have one. If you are just doing occasional work for friends or neighbors, you do not need to. Businesses usually want this information for their records, so ask them if they need it before you send the invoice.
What if the person wants to pay me in installments instead of all at once?
You can create a payment plan. Write on the invoice something like "Payment plan: $250 due by [date], $250 due by [date]." Make sure you both agree to this before you send the invoice, and put it in writing so there is no confusion later. You can also send separate invoices for each payment if that is clearer.
Do I need to charge sales tax on my invoice?
Sales tax rules vary by state and by what you are selling or doing. If you are selling a product, you usually need to charge tax. If you are providing a service, you usually do not. Check your state's tax website or ask a local accountant what applies to you. If you do need to charge tax, add it as a separate line on the invoice below the amount for your work.