Beyond the bare essentials, a handful of optional additions can make an invoice noticeably more professional and reduce back-and-forth with clients.
Required fields
Invoice number, business and client details, invoice/due dates, itemized charges, tax, and total due — covered in detail in our How to Write an Invoice guide.
Worth adding
- Your logo — a small branding touch that makes an invoice look considerably more professional.
- A purchase order or reference number — if your client issued one, referencing it speeds up their internal approval process.
- Payment terms in plain language — not just a due date, but a note like “Net 30 from invoice date” removes any ambiguity.
- A thank-you note — small, but it costs nothing and reads well.
- Late fee policy — stating it upfront (even if you rarely enforce it) sets expectations before a payment is ever late.
The complete invoice checklist
| Element | Required? | Notes |
|---|---|---|
| The word “Invoice” (or “Tax Invoice”) | Yes | Distinguishes it from a quote or receipt |
| Unique invoice number | Yes | Sequential; never reused |
| Invoice date | Yes | Starts the payment-term clock |
| Due date / payment terms | Strongly recommended | Write the actual date |
| Your business name, address and contact | Yes | Legal or trading name |
| Client name and billing address | Yes | Company’s legal name |
| Itemized goods/services | Yes | Description, quantity, unit price, line total |
| Subtotal, tax and total due | Yes | Show the tax rate and amount |
| Tax registration number | If registered | VAT, GST, ABN, GSTIN, etc. |
| Payment instructions | Strongly recommended | Bank details, payment link |
| PO or reference number | If the client uses them | Often required for approval |
| Logo, thank-you note, late-fee terms | Optional | Professional touches |
Payment details that get you paid faster
The easier you make it to pay, the faster you’re paid. Include everything the client needs in one place:
- Bank transfer: account name, bank name, account number and routing/sort code — plus IBAN and SWIFT/BIC for international payments.
- Online payment: a payment link from your payment provider that your client can click.
- Cheque: who to make it payable to and where to send it.
- Payment reference: ask clients to quote the invoice number so you can match payments.
Special situations
- Deposits: show the deposit already received as a deduction so the balance is clear.
- Recurring work: state the period covered (“Retainer — June 2026”).
- Reverse charge (EU/UK B2B): where the customer accounts for VAT, add a reverse-charge note instead of charging VAT, plus both parties’ VAT numbers.
- Tax-exempt sales: note the exemption reason or the customer’s resale/exemption certificate number.
- Foreign currency: show the currency code (USD, EUR) and, if relevant, the exchange rate used.
- Industry details: VIN for auto repair, CPT codes for medical receipts, property address for landlords — see our industry templates.
What not to include
- Internal notes or shorthand the client won’t understand.
- Unagreed charges — anything new should be discussed before it appears on an invoice.
- Sensitive personal data that isn’t needed (e.g. full personal ID numbers).
- Conflicting dates or terms that differ from your contract.
Country-specific invoice requirements
| Country / region | Notable requirements when tax-registered |
|---|---|
| United States | No federal format; show sales tax separately where charged |
| United Kingdom | VAT number, date of supply, VAT rate and amount, customer details |
| European Union | VAT numbers (both parties for B2B cross-border), sequential numbering, reverse-charge wording where applicable |
| Canada | GST/HST registration number; requirements increase with the invoice value |
| Australia | “Tax invoice”, ABN and GST amount for GST-registered sellers |
| India | GSTIN, HSN/SAC codes, place of supply; e-invoicing for larger businesses |
| Pakistan | NTN/STRN for sales-tax-registered businesses, sales tax shown separately |
| UAE | “Tax invoice”, TRN and VAT amount for VAT-registered businesses |
A general overview — check your tax authority’s current rules before relying on it.
An invoice that includes everything
Picture a well-built invoice from top to bottom: your logo and business details on the left, “INVOICE” with the number, date and due date on the right; the client’s billing details below; a clear table of items with quantities, prices and tax; a totals block with subtotal, discount, tax, shipping and a bold total due; and finally payment instructions and a short thank-you. That’s exactly the layout our free generator produces — fill in the form and every element on this checklist is in place.
Frequently asked questions
What are the mandatory parts of an invoice?
At minimum: the word ‘Invoice’, a unique number, the invoice date, the seller’s and buyer’s details, a description of goods or services with amounts, any tax, and the total due. Tax-registered businesses must usually add their tax number.
Should I put bank details on an invoice?
Yes, if you want to be paid by bank transfer. Include everything needed for the payment, plus IBAN and SWIFT/BIC for international clients.
Does an invoice need a signature?
Generally no. A signature isn’t required for an invoice to be valid in most countries.
Our free generator includes every field above — logo upload, reference numbers, and custom notes all built in.
Create Free Invoice