Invoicing
How to Create an Invoice: A Step-by-Step Guide
An invoice is a request for payment that records what you sold, who you sold it to and when payment is due. This guide explains how to generate an invoice correctly, what every invoice must include, and how to export an invoice PDF for free without signing up for anything.
By Arshad Hossain · Published · Updated
The short version
- Every invoice needs a unique number, an issue date and an explicit due date.
- Itemize clearly. Vague descriptions are the most common reason invoices get queried.
- State payment terms and bank details on the invoice itself, not only in a contract.
- Send it the day the work is finished, not at month end.
How to create an invoice: step by step
- 1
Add your business details
Enter your business name, address, email and phone number, plus your tax or VAT registration number if you have one. Upload your logo so the invoice is clearly identifiable as yours.
- 2
Add your client details
Enter the client business name, the contact person and their billing address. Billing the correct legal entity matters if you ever need to chase payment.
- 3
Give the invoice a unique number and dates
Assign a sequential invoice number such as INV-001, then set the issue date and the payment due date. Never reuse an invoice number.
- 4
List what you are charging for
Add one line item per product or service with a clear description, quantity and unit rate. Specific descriptions reduce payment queries.
- 5
Apply tax, discounts and shipping
Set your tax or VAT rate, add any agreed discount as a percentage or fixed amount, and include shipping if relevant. The invoice subtotal and total are calculated automatically.
- 6
State your payment terms
Write your payment terms and bank or payment details in the notes field, for example Net 30 or payment due within 14 days, along with any late payment charge.
- 7
Export the invoice as a PDF and send it
Choose an invoice template, then export the invoice as a PDF and email it to your client, or share a link. Keep a copy for your accounting records.
What must be included on an invoice
Requirements vary by country, but almost every jurisdiction expects the same core information. Missing any of these is the most common reason an invoice is queried or delayed.
- The word "Invoice" clearly displayed on the document
- A unique, sequential invoice number
- Your business name, address and contact details
- Your tax, VAT or company registration number where applicable
- The client business name and billing address
- The invoice issue date and the payment due date
- An itemized description of the goods or services supplied
- Quantity, unit price and line total for each item
- The subtotal, any discount, the tax rate and tax amount
- The total amount payable and the currency
- Payment terms and how the client should pay you
How to number your invoices
Invoice numbers must be unique and should run in sequence so that your records have no gaps. A simple sequential format like INV-001, INV-002, INV-003 works for most small businesses and freelancers.
If you invoice many clients, you can prefix the client or the year, for example 2026-ACME-001. Whatever scheme you pick, stay consistent and never reuse or skip a number, because gaps make bookkeeping and tax reporting harder to reconcile.
Setting payment terms that actually get you paid
Payment terms tell the client exactly when payment is due. Net 30 means payment is due 30 days after the invoice date. Shorter terms such as Net 14 or due on receipt generally get you paid faster, particularly for freelance and small business work.
State the terms in plain language on the invoice itself rather than relying on a separate contract. Include your bank details or payment link directly on the invoice, and if you charge interest or a fee on late payment, say so clearly on every invoice from the start.
Invoice, quotation, estimate or receipt?
These four documents are frequently confused, and sending the wrong one creates confusion about whether money is owed.
A quotation is a fixed price offer sent before work begins. An estimate is an approximate figure that may change. An invoice is sent after the work is done and requests payment. A receipt confirms that payment has already been received.
The sequence for most businesses is quotation first, then invoice once the work is complete, then a receipt once the client has paid.
How to generate an invoice PDF for free
You do not need accounting software or a paid subscription to produce a professional invoice. Fill in the invoice fields in your browser, pick a template, and export a PDF with proper A4 formatting.
QuillBill generates the invoice entirely on your device. There is no account, no email required, no watermark on the exported PDF, and your client and pricing data is never sent to a server.
Common invoicing mistakes to avoid
Most late payments trace back to a small number of avoidable errors.
- Vague line item descriptions that invite questions before payment
- Missing or duplicated invoice numbers that break your records
- No stated due date, which effectively means no deadline
- Billing the wrong legal entity or the wrong contact person
- Leaving off payment instructions or bank details
- Forgetting to apply the correct tax or VAT rate
- Sending the invoice late, which pushes the payment date out with it
How to generate an invoice: common questions
How do I generate an invoice?
Enter your business details, the client's legal entity and address, a unique invoice number, the issue and due dates, and itemized line items with quantities and rates. Apply tax as a separate line, state your payment terms and bank details, then export the document as a PDF.
What information is legally required on an invoice?
Requirements vary by country, but almost all expect a unique identifying number, both parties' names and addresses, a clear description of what is supplied, the dates, the amount due and the tax treatment. VAT and GST registered businesses have longer lists again.
What is the difference between an invoice and a bill?
They describe the same document from opposite sides. What you send as an invoice arrives at the client as a bill they owe. "Invoice" is the standard term in business-to-business trade; "bill" is more common in consumer and retail contexts.
When should an invoice be issued?
As soon as the work is complete or the goods are delivered, or at agreed milestones on longer projects. Payment terms run from the invoice date, so issuing late pushes your payment date out by exactly as long as you waited.
Can I edit an invoice after sending it?
Do not silently alter a sent invoice. If it was wrong, issue a credit note cancelling it and then a corrected invoice with a new number, so your numbering sequence and your client's records both stay auditable. Quietly reissuing the same number creates a reconciliation problem.
Should I put my bank details on an invoice?
Yes — an invoice without a way to pay it is a notification rather than a request. Include everything needed to complete the transfer, including IBAN, SWIFT or routing numbers for cross-border payments, and verify them carefully, since invoice payment fraud targets exactly this field.
Do I need to sign an invoice?
No. Invoices do not require signatures in ordinary commercial practice, unlike quotations and proposals where acceptance matters. A few clients and some jurisdictions request signed invoices for specific purposes, so follow the requirement when you are given one.
Frequently Asked Questions
How do I create an invoice for free?
Can I create an invoice without a company?
What invoice number should I start with?
Do I need to charge tax on my invoice?
What is the difference between an invoice and a receipt?
More on invoicing
- Invoice Example: A Completed Invoice, Field by Field
A completed invoice with every field annotated, plus the versions that get queried and why.
- How to Create an Invoice for Free
Four routes to a free invoice compared on speed and accuracy, plus the pre-send checks that stop invoices being queried.
- Free Invoice Templates: Choosing a Format That Actually Works
Choosing an invoice template by file format and industry, the layout decisions that affect payment speed, and why template sites hold 1,000 near-identical files.
- Freelance Invoicing: A Complete Guide
Invoicing as a freelancer end to end: your first invoice, rates, deposits, international clients and records.
- Invoice Numbering Systems That Survive an Audit
Designing an invoice numbering system that survives an audit: sequential vs dated schemes, why gaps matter, resetting annually, and what to do after a mistake.
- International Invoicing: Currency, Fees and Getting Paid
Invoicing across borders: choosing the currency, who pays the transfer fees, exchange rate risk, and getting paid without losing a chunk to intermediary banks.
- Invoice Record Keeping: What to Keep and For How Long
How long to keep invoices, what counts as an acceptable record, digital versus paper, and building a filing system you can actually search under pressure.
- What Is a Proforma Invoice?
What a proforma invoice is, when to send one, and how it differs from a quotation and a commercial invoice.
- Receipt Template: What a Receipt Must Show
What a receipt has to show, how it differs from an invoice, and when a client is entitled to one.
- Purchase Order vs Invoice
Who issues a purchase order, who issues an invoice, and why a missing PO number stops you getting paid.
- Purchase Order Template: What a PO Must Include
Writing a purchase order that a supplier can act on and an invoice can be matched against.
Create your invoice now
Free, no sign-up, no watermarks. Your data stays in your browser.
Create Invoice Free