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Finishing the work is the easy part. Getting paid depends on the invoice you send, and one missing detail can stall payment for weeks. If you are not sure how to write an invoice that looks professional, here is exactly what to include, in what order, and what the tax rules in your country demand.
What Does a Professional Invoice Look Like?
A professional invoice is one page, one table, and one clear total. Your business name and logo sit at the top, the client's name and address sit beside them, and the work you did sits in a table below. The number the client owes is the biggest, boldest thing on the page.
A wedding photographer in Austin, Texas sends a $2,800 invoice after every event. Her client's bookkeeper finds the invoice number, the date, and the total in ten seconds, because every invoice she sends uses the same layout. That consistency is what reads as professional — not fancy fonts or colors.
Use your logo, even a simple text wordmark, and add your email and phone number. The client should never have to ask who sent the invoice or how to reach you. Keep the layout identical every time, so clients recognize your invoice the way they recognize a trusted brand.
If a client has to search for the amount, you have made paying you harder than it needs to be. A one-page layout also survives printing and accounting software without falling apart.
What Must Every Invoice Include?
Some elements are non-negotiable. Miss one, and the client's accountant or your tax authority will push the invoice back. Include these on every single invoice:
- Your full name or business name, address, and contact details
- The client's name and billing address
- A unique invoice number — never reuse one
- The invoice date and the payment due date
- Each product or service, with quantity, rate, and amount
- The subtotal, any tax, and the final total
Payment details belong on every invoice too: your bank account number, routing or sort code, and any payment link. A freelance developer in Toronto added his account details after his first client paid 19 days late because the bank info was buried in an email thread. That single line cut his average payment time in half.
Country-specific extras come next — a VAT number in the UK, GST/HST registration in Canada, an ABN in Australia. The next four sections explain exactly when each one applies. Get the base list right first, and the rest is just additions.
How to Write an Invoice Step by Step
Here is the order that works, whether you start from a blank document or afree invoice generator that does the math for you.
- Add your business details and logo at the top.
- Add the client's name, company, and billing address.
- Add a unique invoice number, the issue date, and the due date.
- List each service with a quantity, rate, and amount.
- Add the subtotal, any tax, and the final total.
- Add your payment details, then send the invoice as a PDF.
Double-check the math before you send. A copywriter in Chicago once billed 40 hours of editing at $95 an hour and wrote $3,700 instead of $3,800. The client paid the wrong amount, and fixing it took two emails and nine days.
Read the invoice top to bottom once, out loud if you have to. Check the client's name spelling — clients notice — and confirm the due date is on the page. Then send it the same day, while the work is fresh in both your minds.
How to Write an Invoice in the United States
The US has no federal invoice format and no federal sales tax. Sales tax is decided state by state, and services from freelancers are exempt in most states — so a US invoice usually has no tax line at all. If your state does charge sales tax on your work, register with that state and add its rate.
Every US client who pays you more than $600 in a year will ask for a W-9 form so they can file a 1099-NEC. Send the W-9 before the invoice, not after. A freelance editor in Portland, Oregon invoiced a publisher $2,400 for a book manuscript; Oregon has no sales tax, so the total stayed $2,400, and her W-9 was already on file.
You still owe tax on the income itself — self-employment tax is 15.3% on your profit. Add your EIN or Social Security number if the client asks, and keep copies of every invoice for at least three years.
How to Write an Invoice in the United Kingdom
If you are VAT registered, every invoice must show your VAT number — GB followed by nine digits — plus the VAT rate, the VAT amount, and the total including VAT. Registration becomes compulsory once your taxable turnover passes £90,000 in any 12 months. You can register before that — a Bristol copywriter who registered at £20,000 turnover reclaimed £250 of VAT on a new laptop in her first quarter.
Not registered? Your invoices must not show VAT, but they still need your company name and registered office address. A London graphic designer charging £800 for a brand identity project adds £160 VAT at 20% — her invoice shows £800 + £160 = £960, with her VAT number on it. Her client's accountant can then claim the £160 back as input VAT, which is exactly why the number has to be there.
Send the invoice within 30 days of finishing the work. Delayed invoices are the most common reason UK freelancers wait two months for money that was owed in one.
How to Write an Invoice in Canada
Canada runs on GST and HST. You must register once your revenue passes $30,000 over four consecutive calendar quarters, and you charge from the day you cross that line. The rate depends on your province: 5% GST in Alberta and British Columbia, 13% HST in Ontario, and 15% HST in Nova Scotia and New Brunswick.
A Toronto web designer invoices $2,000 for a website and adds 13% HST — $260 — for a total of $2,260. Her invoice shows her GST/HST registration number and lists the HST as a separate line. That separate line matters because her client's accountant claims the input tax credit on it.
Quebec adds its own layer: 9.975% QST on top of 5% GST. If you bill Quebec clients, show both taxes separately on the invoice.
How to Write an Invoice in Australia
Australia runs on two numbers: your ABN and your GST registration. You need an ABN before you invoice at all — clients can legally withhold 47% of your payment if your invoice has no ABN. GST registration becomes compulsory once your annual turnover passes $75,000, and then every invoice changes.
A GST-registered invoice must say "tax invoice", show your ABN, and state the GST amount — 10% of the price. A Melbourne copywriter earning $80,000 a year bills her $5,500 annual content package as $5,000 plus $500 GST. Her client's bookkeeper checks the ABN and the GST line before approving payment, so both must be correct the first time.
If your turnover is under $75,000, you can still register voluntarily — a Brisbane handyman on $40,000 a year registers so his clients can claim the GST back on his work. Just keep the threshold in mind as you grow.
Invoice Writing Mistakes That Delay Payment
These six mistakes delay more invoices than anything else, and all of them are easy to fix.
- Skipping the invoice number. Clients' accounting systems reject invoices without one, and "payment reference: the website work" is not a number.
- Vague line items. "Services rendered — 40 hours" makes clients slow down and question the bill. "Website development — 40 hours at $75/hr" gets approved.
- Missing bank details. The most common reason invoices go unpaid is that the client has to ask where to send the money. Put the details on the invoice, every time.
- Sending a Word document. Clients can edit it, and edited numbers cause disputes. Send a PDF — that is the version that gets paid.
- Leaving the due date off. "Please pay soon" is not a payment term. "Due 14 days after issue" is.
- Forgetting your VAT or GST number. A UK client cannot claim input VAT without your VAT number, so their accountant will bounce the invoice back.
Frequently Asked Questions
Do I need an invoice number on every invoice?
Yes. Invoice numbers help you, your client, and their accountant keep track of payments. Use a simple sequence — 001, 002, 003 — and never reuse a number, even if an invoice is cancelled. Cancel with a credit note instead of deleting the invoice.
Should I add tax to my invoice?
Only if you are registered for VAT, GST, or HST, or if your state charges sales tax on services. In the US, most states do not charge sales tax on services. In the UK, Canada, and Australia, registration thresholds decide it — £90,000 turnover, $30,000 over four quarters, and $75,000 respectively.
What if my client wants changes after I send the invoice?
Do not edit the original invoice and resend it — that breaks your numbering and your records. Send a credit note for the difference or issue a new invoice with a new number. Your accountant will thank you.
What payment terms should I put on an invoice?
Net 14 or net 30 — payment due 14 or 30 days after the invoice date — are the most common. Shorter terms suit smaller jobs. If you want to get paid fast, offer a 2% discount for payment within seven days.
Can I send an invoice by email, or does it need to be posted?
Email is fine everywhere covered in this guide. Attach a PDF, not a Word document, and keep a copy of the sent invoice for your records. Ask each client once if they have a billing email, and note it down.
What is the difference between an invoice and a receipt?
An invoice asks for payment and lists what was done and what is owed. A receipt confirms that the payment actually landed. Send a receipt after the money arrives — you can create one free with our receipt generator, no sign-up needed.
What payment methods should I offer clients?
Bank transfer is the safest and most common. Add payment links like PayPal or Stripe for international clients, and always show your account details in full — name, account number, and routing or sort code. Every missing detail is a delayed payment.
Create Your Invoice Now — Free
Invoha is a free invoice generator that handles the layout, the math, and the PDF for you. Fill in your details and your invoice is ready to send in under a minute — no sign-up, and your data never leaves your device.