The fields every invoice needs
Before the steps, here is the short list of details that turn a document into a valid invoice. Most countries require the same core set; if you are registered for sales tax or VAT, a few more fields apply (covered in step 5). Getting these right is what makes the invoice acceptable to your client’s accounts team and to a tax authority.
- The word "Invoice"
- A clear label so the document is not mistaken for a quote, order or receipt.
- Your business details
- Your name or trading name, address, and contact details, plus any tax or company registration number.
- The client details
- The name and address of the person or company you are billing.
- A unique invoice number
- A sequential reference that identifies this invoice and never repeats.
- Issue date and due date
- The date you raised the invoice and the date payment is due.
- A description of what you sold
- A line for each item or service, with quantity and price.
- The amount due
- The subtotal, any tax, and the final total to be paid.
- How to pay
- Your bank details or payment link and accepted methods.
Step 1: Add your details
Start with who is sending the invoice. Put your business name (or your own name, if you trade as a sole proprietor) at the top, followed by your address, email and phone number. If you have a logo, this is where it goes — it makes the invoice look professional and easy to recognise. Include any registration numbers that apply to you: a company number, a tax identification number, or a VAT/GST number if you are registered. Clients often need these to process your invoice and to reclaim tax, so leaving them off can delay payment.
Step 2: Add the client
Next, address the invoice to the right party. Use the client’s legal or trading name and their billing address, not just a contact’s personal name — invoices that go to the wrong entity get bounced back. If you are billing a company, ask for the correct accounts-payable email and any purchase order (PO) number they want quoted; many businesses will not pay an invoice that lacks the PO reference. For cross-border business-to-business work, you may also need the client’s VAT or tax number on the invoice.
Step 3: Give it a unique number and dates
Every invoice needs a unique, sequential number so you and your client can refer to it unambiguously and so your records have no gaps. A simple scheme like 2026-001, 2026-002 works; the important thing is that numbers never repeat or skip without reason, because gaps are a common audit flag. Add two dates: the issue date (when you raise the invoice) and the due date (when payment is expected). Spelling out the due date as a real calendar date, rather than just „Net 30“, removes any doubt about when the money is owed.
Step 4: Itemise the work
This is the heart of the invoice. List each product or service on its own line with a short, specific description, the quantity or hours, the unit price, and the line total. Clear descriptions („Homepage redesign – 12 hours“ rather than „design work“) reduce questions and speed up approval. Add the line totals to get the subtotal — the amount before any tax or discount. If you offered a discount, show it as its own line so the maths is transparent.
Step 5: Add tax
If you are registered for VAT, GST or sales tax, you generally have to charge it and show it separately. Apply the correct rate to the taxable subtotal, display the tax rate and the tax amount as their own lines, and include your tax registration number. For cross-border business-to-business supplies, the tax may shift to the buyer under the reverse charge — in that case you show a zero-VAT line, quote both tax numbers, and add a note such as „Reverse charge“. If you are not registered for any sales tax, you simply skip this step, and it is good practice to note that no tax is charged.
Step 6: Show the total and payment terms
State the grand total due in a single, prominent figure, and name the currency clearly so there is no ambiguity on an international invoice. Then spell out the payment terms: when payment is due (for example, within 14 or 30 days), the accepted payment methods, and your bank details or a payment link. If you charge interest or a fee on late payments, state it here. Clear, visible terms are the single biggest lever on getting paid on time, so keep them short and unmissable.
Step 7: Send and track
Send the invoice promptly, usually as a PDF attached to a short, polite email, to the right billing contact. Note the date you sent it and the due date, and keep a copy for your own records — most tax authorities require you to retain invoices for several years. If payment has not arrived by the due date, send a friendly reminder; a brief follow-up a few days after the due date resolves most late payments without friction. Tracking which invoices are sent, paid and overdue is what stops income slipping through the cracks.
Frequently asked questions
What has to be on an invoice?
At a minimum: the word "Invoice", your business name and contact details, the client's name and address, a unique invoice number, the issue and due dates, a description of what you sold with quantities and prices, the total due, and how to pay. If you are registered for VAT, GST or sales tax, you also show your tax number, the tax rate and the tax amount.
How do I number invoices?
Use a unique, sequential number that never repeats, such as 2026-001, 2026-002, and so on. You can prefix it with the year or a client code, but avoid gaps and duplicates because they are a common audit flag. A generator that assigns the next number automatically is safer than numbering by hand.
Do I need to charge tax on my invoice?
Only if you are registered for VAT, GST or sales tax. If you are, you generally charge the correct rate and show it as a separate line with your tax number. If you are not registered, you do not add tax, though cross-border business sales may require a "reverse charge" note where the buyer accounts for the tax instead.
What payment terms should I set?
Common terms are payment within 14 or 30 days of the invoice date. State the due date as a real calendar date, list the methods you accept and your bank details or payment link, and mention any late-payment fee. Shorter terms and clearly visible details tend to get you paid faster.
What is the difference between an invoice and a receipt?
An invoice is a request for payment issued before the client pays; it states what is owed and when. A receipt is proof of payment issued after the money has been received. The same transaction can produce both: the invoice first, the receipt once it is settled.
How do I send an invoice?
Export it as a PDF and email it to the client's billing contact with a short, polite note, or share a payment link. Send it promptly, keep a copy for your records, and follow up with a reminder if it is not paid by the due date.