How to Write an Invoice: A Simple Template and Guide

An invoice looks like a simple document, and mostly it is - but the fields that seem optional are usually the ones that get an invoice bounced back, ignored, or paid weeks later than it should have been. Here's every piece an invoice actually needs, in the order it should appear, and why each one earns its place.

1. Your business details

Name, address, and at least one way to reach you - email or phone. If you're VAT registered or have a business registration number, it goes here too. This isn't decoration; it's what lets the client's accounting team file the invoice without emailing you to ask who it's even from.

2. The client's details

The company or person being billed, addressed the way their own records would recognize - matching the name on the contract or purchase order, not a nickname from your email thread. Mismatched names are a common reason invoices sit in an approval queue.

3. An invoice number

Sequential, unique, and never reused. It's how both sides refer to the invoice later - in payment confirmations, in disputes, in your own bookkeeping - and skipping it makes an invoice look improvised rather than issued by a real business.

4. Issue date and due date

The issue date anchors your payment terms; the due date should be an actual calendar date, not "within 14 days" that the client has to calculate themselves. Do the math for them.

5. A clear line-item breakdown

Each item described the way the client would describe it - not your internal project shorthand - with quantity, rate, and line total. A single lump "services rendered" line is the fastest way to invite a "can you break this down?" email that adds another week to payment.

6. Subtotal, tax, and total

Shown as separate lines, not folded together, especially if you charge VAT or sales tax - the client's bookkeeping needs the pre-tax and tax amounts split out regardless of how you present it visually.

7. Payment details

Bank account or IBAN, payment link, or however you actually want to get paid - in the same place on every invoice you send, not buried in a signature block. If a client has to search for how to pay you, that search is one more excuse for the payment to wait.

8. Payment terms, stated plainly

Net 15, Net 30, due on receipt - whatever you've agreed, written down on the invoice itself, not left to memory. It's the one line that turns "I'll get to it eventually" into an actual deadline.

The template, assembled

Put those eight pieces on one page, in that order, and you have an invoice that answers every question a client or their accounts team could ask before they've had to ask it. That's the whole template - the format around it (PDF, spreadsheet, a link) matters far less than making sure nothing on this list is missing.

InvoiceCraft builds every invoice from this exact structure automatically - you fill in line items and a client, and the numbering, totals, and layout take care of themselves.