What Is an Invoice? Explained for Businesses
An invoice is a document that a business or service provider sends to a customer to request payment for goods or services. It outlines what was provided, how much the customer owes, and when and how they should pay.
A typical invoice includes the business and customer details, a breakdown of the products or services, the total amount due, and payment instructions. This gives customers a clear picture of what they’re paying for and helps businesses keep track of payments and outstanding balances.
But what exactly should you include on an invoice, and how is it different from a receipt or a quote? Let’s look at the main parts of an invoice, the information you need, and how invoices work in everyday business.
The Parts of an Invoice
Most professional invoices contain nine main parts. Each serves a purpose, from identifying the customer to explaining how much they owe.
Invoice part | What it includes | Example |
|---|---|---|
1. Invoice number | A unique number used to identify and track the invoice | INV-1048 |
2. Invoice date | The date the invoice was issued | October 14, 2026 |
3. Seller information | Business name, address, and contact details | Miller Electrical Services |
4. Customer information | Name and billing details of the customer | ABC Property Management |
5. Description of goods or services | A list of products sold or work completed | Electrical outlet replacement |
6. Quantity and rate | Number of items or hours and the price charged | 2 hours × $85 |
7. Subtotal and taxes | Charges before adjustments and any applicable taxes | Subtotal: $170 |
8. Payment terms and due date | When payment is expected and how to pay | Net 30 |
9. Total amount due | The final amount the customer needs to pay | $170 plus applicable tax |
Together, these details make an invoice easier to understand and pay. The invoice number helps you and your customer keep track of the transaction, while clear descriptions explain each charge. The due date tells the customer when to pay, and the total amount due should be easy to spot, even when taxes or discounts are included.
Keep in mind that not every detail is legally required on every invoice. The rules can vary depending on your business, location, and the type of transaction.
For a closer look at individual charges, see our guide to invoice line items.
What to Include on an Invoice
A clear invoice gives your customer the information they need to understand the charges and make a payment. Use this 15-point checklist to make sure you haven’t missed anything important.
Keep in mind, not every item is required for every business. Some are simply good practice, while others may be required by state law, tax rules, or your agreement with the customer.
Invoice Checklist: 15 Important Details
Information | Classification | Why it matters |
|---|---|---|
1. Invoice number | Recommended | Makes each invoice easy to identify and track |
2. Invoice date | Recommended | Records when the invoice was issued |
3. Business name | May be legally required | Identifies the seller or service provider |
4. Business contact information | Recommended | Gives customers a way to ask questions |
5. Customer name | Recommended | Identifies who is being billed |
6. Customer billing address | Situation-dependent | Helps with billing records and payment processing |
7. Description of products or services | Recommended | Explains what the customer is paying for |
8. Quantities or hours | Recommended | Shows how charges were calculated |
9. Unit rates | Recommended | Makes individual prices clear |
10. Subtotal | Recommended | Shows the amount before taxes or adjustments |
11. Applicable taxes | May be legally required | Shows taxes charged when required |
12. Discounts or deposits | Situation-dependent | Explains reductions or payments already received |
13. Total amount due | Recommended | Clearly states the payment requested |
14. Payment due date and terms | Recommended | Tells customers when payment is expected |
15. Payment instructions | Recommended | Explains how customers can pay |
Recommended fields may still be required for certain transactions. For example, some companies require a purchase order number before they’ll process an invoice.
If you’re not sure what’s required, check your state’s tax rules or any regulations that apply to your industry.
Additional Invoice Details for Contractors
Contractors sometimes need more information than businesses selling standard products or services.
Depending on the job, consider including:
- Job or service address: Shows where the work was completed, especially when the billing address is different.
- Contractor license number: Identifies the licensed business and may be required on certain documents.
- Permit number: Connects the invoice to a permitted project when relevant.
- Late-payment terms: Explains any fees or conditions already agreed upon with the customer.
For example, California requires contractors to include specific information, including their license number, in qualifying home improvement contracts. Requirements for invoices and other documents can differ.
The California Contractors State License Board explains what must be included in home improvement contracts.
Other Useful Invoice Details
Some invoices also include:
- A PO number or purchase order number to match the invoice to an approved purchase.
- A separate remit-to address if payments should be sent somewhere other than the business address.
- Additional billing information requested by the customer.
- A short thank-you note or job reference.
If your customer requires a purchase order before work begins, you can use InvoiceFly’s purchase order generator to create one.
The goal is to give your customer everything they need to understand and pay the invoice, without adding unnecessary details.
Example: A Contractor Invoice
A contractor invoice is a good example because it often includes several types of charges.
Imagine a plumbing company has completed a residential repair. The customer paid a $150 deposit before the work began and now owes the remaining balance.
Here’s what the invoice could look like.
ClearFlow Plumbing Services: Invoice #PL-2048
INVOICE
From:
ClearFlow Plumbing Services
1250 Oak Street
Austin, TX 78701
billing@clearflowexample.com
Bill to:
Jordan Miller
4807 Maple Avenue
Austin, TX 78745
Service address:
4807 Maple Avenue, Austin, TX 78745
Invoice details | |
Invoice number | PL-2048 |
Invoice date | October 14, 2026 |
Payment due | October 28, 2026 |
Service completed | October 13, 2026 |
Work completed: Residential plumbing repair
Description | Quantity | Rate | Amount |
|---|---|---|---|
Plumbing service call and inspection | 1 | $75 | $75 |
Replace leaking kitchen supply line | 2 hours | $90 | $180 |
Replacement valve and supply line materials | 1 | $120 | $120 |
Subtotal | $375 | ||
Sales tax on taxable materials (8.25%) | $9.90 | ||
Invoice total | $384.90 | ||
Deposit already paid | -$150 | ||
Remaining balance due | $234.90 |
Payment terms: Payment due within 14 days.
Payment instructions: Pay using the payment details provided with this invoice. Reference Invoice #PL-2048.
Note: Thank you for choosing ClearFlow Plumbing Services.
How This Invoice Works
This invoice breaks down the service call, labor, and materials so the customer can see exactly what they’re paying for.
It also shows the full cost of the job, deducts the $150 deposit already paid, and makes the remaining balance easy to find.
Why is sales tax shown only on materials?
In this example, the plumber and customer have agreed to bill labor and materials separately.
In Texas, labor for residential repairs is generally not taxable. When a qualifying contract separates labor and materials, sales tax applies to the materials, but not the labor. The rules are different for lump-sum contracts and commercial jobs.
You can read more in the Texas Comptroller’s guide to real property repair and remodeling.
The prices and 8.25% tax rate are just examples, not a verified calculation for this address. When preparing your own invoices, always check the tax rules and rates that apply to your work.
Tip: You can create a similar invoice using our invoice templates.
Types of Invoices
Businesses use different types of invoices depending on what they’re selling, how they charge, and when payment is expected.
Invoice type | What it means | Typical use |
|---|---|---|
Standard invoice | Requests payment for products or services | Everyday business transactions |
Records a sale and the amount owed | Product and service sales | |
Outlines a proposed sale before final billing | Preliminary agreements and international trade | |
Issued regularly on an agreed schedule | Monthly cleaning or maintenance | |
Requests payment for work completed so far | Construction and long-term projects | |
Requests payment when a project stage is completed | Project-based services | |
Prepared by the customer under an agreed arrangement | Certain supplier relationships | |
Exchanged in a digital format that can be processed electronically | Digital business transactions |
The type of invoice you use depends on the work you’re doing and how you’ve agreed to bill your customer.
For a one-time job, a standard invoice is usually enough. If you provide regular services, such as monthly cleaning or maintenance, you might use recurring invoices. For larger projects, contractors often use progress or milestone invoices to bill customers as work is completed.
If you’re outlining a proposed sale, especially for an international transaction, a proforma invoice generator can help you prepare the details before issuing a final invoice.
Electronic invoicing, or e-invoicing, is a little different. It uses structured digital data that accounting systems can process automatically. Simply emailing a PDF invoice doesn’t necessarily count as e-invoicing.
For a closer look at each option, see our guide to the types of invoices.
Invoice vs. Receipt, Bill, Quote, and Purchase Order
Invoices are often confused with other business documents. The main difference is when they’re used and what they’re meant to communicate.
Invoice vs. Receipt
The main difference is simple: an invoice requests payment, while a receipt confirms that payment has been made.
For example, a contractor sends an invoice for a completed repair. Once the customer pays, they can issue a receipt as proof of payment.
Learn more about the differences between an invoice vs receipt.
Invoice vs. Bill
Invoices and bills are closely related, and the terms are often used interchangeably.
The difference usually comes down to perspective. You send an invoice to request payment, but you receive a bill when you owe someone money. And while some bills are due immediately, others give you time to pay.
Read our invoice vs bill guide for a closer look.
Invoice vs. Quote
A quote tells your customer what a job will cost before work begins. An invoice tells them what they owe under the agreed terms.
For example, a landscaper might quote $600 for a yard cleanup, then send an invoice once the work is finished.
If the final price isn’t certain, you might provide an estimate instead. You can also learn more about quotations and the differences between a quote and an invoice.
Invoice vs. Purchase Order
A purchase order comes from the buyer and confirms what they want to purchase, often before work begins. An invoice comes from the seller and requests payment.
For example, a property management company might issue a purchase order authorizing electrical repairs. Once the electrician completes the work, they send an invoice for payment.
How to Make and Write an Invoice
Once you know what information belongs on an invoice, you’re ready to put it together. There’s a small difference between making an invoice and writing one.
Making an invoice is about creating the document itself, from choosing a template or software to adding your details, calculating the total, and getting it ready to send.
Writing an invoice is about the information you include and how you word it, especially when describing your work, explaining charges, and setting payment terms.
We have step-by-step guides to help with both:
- How to make an invoice walks you through creating a finished invoice.
- How to write an invoice explains what to put in each section, with examples you can adapt for your business.
If you’d rather get started right away, you can use InvoiceFly’s free invoice generator to create your invoice online.
Create Professional Invoices With Invoice Fly
A good invoice doesn’t need to be complicated. As long as it clearly explains the work you’ve done, what your customer owes, and how to pay, you’re off to a good start.
InvoiceFly makes it easier to put everything together. You can create professional invoices, keep customer details organized, and track payments in one place, without spending hours on paperwork.
That means less time dealing with invoices and more time focusing on your business.
FAQs about Invoices
An invoice is a document businesses send to request payment for products sold or services provided. It includes details such as pricing, payment terms, due dates, and customer information.
Invoices are used to request payment and keep records of business transactions. They help businesses track sales, manage payments, and maintain accounting documentation.
No. An invoice requests payment, a bill is usually due immediately, and a receipt confirms that payment has already been made.
Start with a simple template that includes the basics: your name, the client’s name, what you’re charging for, and the total. Use a free invoice generator or software to make it easier to create, send, and track invoices.
Invoices and bills are similar because both request payment, but they are usually used in different situations. Invoices often include payment terms and due dates, while bills are commonly paid immediately.
Most invoices include business and customer information, invoice numbers, payment terms, due dates, product or service descriptions, pricing, taxes, and the total amount owed.
Yes. Some businesses create invoices manually using Word or Excel templates, while others use invoicing software or mobile apps to automate the process.
If an invoice is overdue, payment has not been received by the due date. Businesses often send payment reminders or overdue invoices to follow up on unpaid balances.
An invoice is a request for payment, but sending one doesn't automatically create a legally enforceable contract. Whether payment can be enforced depends on the agreement between the parties, the goods or services provided, and applicable law. For example, an invoice supported by an accepted quote, signed contract, or proof of completed work may help document a valid payment obligation.
No. An unpaid invoice shows the amount requested, not that the customer has paid. A paid invoice may help document a completed transaction, but a receipt, bank statement, or payment confirmation provides clearer proof that payment was received. The IRS recommends keeping invoices, receipts, and other supporting records for business transactions.
An invoice is usually issued by the seller, supplier, contractor, freelancer, or service provider. For example, a plumber sends an invoice to a homeowner after completing a repair, while a freelance designer invoices a business for completed design work.
In some supplier arrangements, the customer may prepare the invoice on the seller's behalf. This is called self-billing.
Create and Send Invoices with Invoice Fly
Whether you’re billing clients weekly, monthly, or per project, Invoice Fly helps you create professional invoices, track payments, and stay organized from anywhere.
