Invoice guide

How to Create a Free Invoice PDF — What to Include, How to Export, How to Get Paid

Most “free invoice generators” make you sign up before you can download anything. This guide covers what every professional invoice must contain, how to number and send invoices correctly, when to charge VAT or GST, and how to download a clean watermark-free PDF in under three minutes — no account required.

• What to include
• Invoice numbering
• Payment terms
• VAT, GST & sales tax
• Generating the PDF
• Sending the invoice
• FAQ

What a professional invoice must include

An invoice is a commercial document and, if you’re VAT or GST registered, a legal one. The more complete it is, the faster it gets paid and the better it holds up if a dispute arises. Every invoice should contain:

• The word “Invoice” — or “Tax Invoice” if you’re VAT/GST-registered (required in most jurisdictions that have a VAT/GST system)
• A unique invoice number — sequential, no gaps; essential for your accounting records and for client reference when they pay
• Issue date — when you raised the invoice; this is the date tax authorities and payment-term clocks refer to
• Due date — when payment is expected; omitting this makes the invoice due “whenever” with no enforceable deadline
• Your full legal name (or business name), address, and contact email
• Client’s full name and address — the legal entity you’re billing; their accounts payable team needs this to match it to a purchase order
• Itemized line items — description of each service or product, quantity, unit price, and line total; vague entries like “Services — $2,400” get questioned by both clients and tax authorities
• Subtotal, discount (if any), tax with rate and label, and total amount due
• Currency — critical if you work with international clients; never leave it ambiguous
• Payment instructions — bank details, transfer method, or payment link; without this, payment is impossible regardless of how professional the rest of the invoice looks

If you’re VAT or GST registered, also include your registration number. Many jurisdictions require it on every tax invoice — the client needs it to reclaim the input tax.

Invoice numbering: keep it simple and sequential

Sequential numbering — INV-001, INV-002, INV-003 — is the standard and what most accountants expect. Variations that work well in practice:

• Year-prefixed: 2026-001, 2026-002 — makes it easy to see at a glance which financial year the invoice belongs to
• Client-prefixed: ACME-001, GLOBEX-001 — useful if you have multiple clients and want to track per-client history
• Combined: ACME-2026-001 — works for agencies with long-standing clients

What to avoid: random numbers, gaps in the sequence (INV-001, INV-004), or reusing a number on a new invoice. Tax authorities in the UK, EU, and Australia flag non-sequential invoice numbering as a potential record-keeping failure. In the event of a VAT inspection, every gap in the sequence requires an explanation.

First invoice ever? Start at INV-001. Don’t overthink it.

Payment terms: what to write and why it matters

Payment terms set the legal clock for when money is owed. The most common options:

Put your payment instructions in the notes field of every invoice — don’t make the client email to ask. Include: bank account number and sort/routing code, IBAN for international transfers, or a direct link to PayPal, Wise, or Stripe if you use one.

If you want to charge late-payment interest, state the rate explicitly on the invoice (“Overdue balances accrue 1.5% per month”). In the UK, the Late Payment of Commercial Debts Act entitles you to charge 8% over base rate on business-to-business invoices without stating it — but stating it makes it impossible to dispute.

VAT, GST, and sales tax: when to charge, what to write

Tax obligations depend entirely on where you’re based, where your client is based, and whether you’ve crossed your jurisdiction’s registration threshold. The short version:

EU B2B exports (reverse charge): If you’re EU-VAT-registered and billing a VAT-registered business in another EU country, you typically apply the reverse charge mechanism — your invoice shows the net amount with no VAT collected, and includes a line: “VAT reverse charged — buyer to account for VAT under Article 194/196 of Directive 2006/112/EC.” Include your client’s VAT number on the invoice.

Generating the PDF with InvoiceQuick

InvoiceQuick runs entirely in your browser. There’s no server, no account, and no watermark. Here’s the full process:

1. Fill in your business and client details

   Enter your name or business name and your client’s name and address. Add your address and contact details in the “Address & contact” field — these appear on the invoice exactly as entered.

2. Set the invoice number and dates

   Enter your sequential invoice number (e.g. INV-042), the issue date (today), and the due date. The invoice preview on the right updates instantly as you type.

3. Add your line items

   Click Add line item for each service or product. Enter a description, quantity, and unit price — InvoiceQuick calculates the line total and running subtotal automatically. Be specific in the description: “Website copywriting — About and Services pages (2,400 words)” is better than “Copywriting.”

4. Set currency, tax, and discount

   Pick your currency from the dropdown (USD, EUR, GBP, and 12 more). If you’re tax-registered, enter your rate and use the label field to write exactly what will appear on the invoice — “VAT @ 20%”, “GST @ 10%”, “HST @ 13%”. Add a flat discount if you’re applying one.

5. Add payment instructions in the Notes field

   This is what gets printed at the bottom of the invoice. Include your bank name, account number, sort/routing code or IBAN, or a payment link. Also state your payment terms: “Payment due within 14 days. Bank transfer preferred.”

6. Download the PDF

   Click Download PDF. Your browser’s print dialog opens with only the invoice on the page — no surrounding UI, no header, no watermark. Select “Save as PDF” (Chrome, Edge, Firefox) or “Print to PDF” as the destination. Name the file with the invoice number: INV-042-ACME.pdf.

   This uses your browser’s native PDF renderer. It works offline, needs no plugin, and produces a clean, professional single-page document at whatever paper size you select (A4 is the global standard; US Letter for US clients).

Sending the invoice

Attach the PDF to an email. Keep the subject line informative and the body short:

Subject: Invoice INV-042 — [Brief description] — Due [date]

Hi [Name],

Please find invoice INV-042 attached for [project name].
Total: [amount] [currency], due by [date].

Payment details are on the invoice — please transfer to [bank/method].
Let me know if you have any questions.

[Your name]

If your client is a large company, check whether they use a vendor portal (SAP Ariba, Coupa, Bill.com, Tipalti) before emailing. Many enterprise AP departments don’t process PDF invoices sent to a generic email address — they require portal submission. Ask your contact before you invoice for the first time.

Follow-up cadence for late payment: on the due date if unpaid, send a short reminder. At 7 days overdue, send a firmer follow-up with the invoice attached again. At 14 days, escalate to a formal overdue notice. Most late payments are administrative delays, not refusals — a calm, prompt follow-up gets most of them resolved before they become disputes.

Create my invoice with InvoiceQuick →

Frequently asked questions

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