Fatura/Invoice HTML

HTML invoices: structure, taxes, delivery and compliance

Every commercial transaction generates a fiscal record, and the invoice — fatura in Portuguese, factura in Spanish, Rechnung in German — is the document that closes the loop between order, delivery and payment. The HTML version has become the default authoring format because it can be styled with CSS, converted to PDF for archival, embedded directly in an email body and translated for international clients, all from a single source. Most billing platforms (Stripe Invoicing, QuickBooks, FreshBooks, Wave, Conta Azul, Bling) render invoices from an internal HTML template before snapshotting them to PDF.

A complete invoice has nine mandatory regions: a header with the sender's logo and the word INVOICE, a sequential invoice number, the vendor block (legal name, address, tax ID), the client block (legal name, address, tax ID), the issue date and due date, a table of line items with description, quantity, unit price and total, the tax breakdown, the grand total, and the payment terms with banking details, PIX key, payment link or QR Code.

International standards: EN 16931, PEPPOL and e-invoicing

The European Union standardised e-invoicing under EN 16931, a semantic model that maps every field of an invoice to a stable identifier. PEPPOL (Pan-European Public Procurement OnLine) extends that standard to a global exchange network used by governments and corporates in Europe, Asia-Pacific and parts of South America. Poland's e-Faktura, Italy's FatturaPA and France's Factur-X are national profiles of the same family. If you sell to public buyers in those markets, structured XML or UBL invoices are mandatory; the HTML version is the human-readable preview.

Brazilian context: NF-e, NFS-e and DSN

In Brazil, the legally binding document is the electronic fiscal note (NF-e modelo 55 for goods, NFS-e for services). Starting in 2023 the Comitê Gestor do Simples Nacional consolidated municipal NFS-e systems into a single national standard (NFS-e Nacional), replacing 5,570 different city implementations. Taxes vary by region and activity: ICMS (state), ISS (municipal), IPI (federal industrialised goods), PIS and COFINS (federal social contributions). An HTML invoice on its own does not replace the NF-e, but it is the customary internal control document for freelancers, MEI services and B2B contracts settled by bank transfer or PIX.

Payment terms, delivery and SaaS billing

Payment terms speak a compact language: "Net 30" means the buyer has 30 days to pay; "2/10 net 30" means a 2% discount applies if paid within 10 days, otherwise the full amount is due in 30. International contracts often use "EOM" (end of month) and "COD" (cash on delivery). For SaaS subscriptions there is an extra layer: pro-rata calculations on mid-cycle upgrades, MRR (Monthly Recurring Revenue) tracking, dunning emails when cards fail and credit notes when a downgrade is requested.

Delivery is usually a hybrid: the HTML body is embedded in an email built with Stripo or Mailmodo, with a PDF attachment generated by wkhtmltopdf, weasyprint or Puppeteer. SMTP, SendGrid, AWS SES and Postmark are the standard transports. Open-tracking pixels and reminder cadences (3 days before due date, on due date, 7 days late, 14 days late) increase the on-time payment rate substantially.

Fraud prevention: the invoice phishing scam

One of the most common B2B frauds is invoice phishing: an attacker compromises a vendor's email account (or just spoofs it) and sends a payment with altered bank details. The recipient pays the criminal's account in good faith. Mitigations: enforce two-channel verification for any change in payment data (a phone call to a known number, never a number from the invoice), sign invoices with S/MIME or DKIM, and standardise PIX keys on the vendor's CNPJ rather than personal CPF where possible.

Frequently asked questions

Should I send the invoice as HTML or PDF? Both. The HTML body inside the email body gives instant readability on mobile, and the PDF attachment serves as the archival copy. Many ERPs ingest both formats automatically.

Is a PIX QR Code mandatory? No. It is optional but greatly improves the time-to-pay because the customer scans and pays in seconds. Adding a pix-copia-e-cola code beside the QR helps desktop users too.

Should the invoice be bilingual? Yes for international B2B. A two-column layout with Portuguese on the left and English on the right is the conventional pattern. For documents with legal weight, the original language prevails.

Do invoice numbers have to be sequential? Yes. Brazilian tax authorities, the IRS and most European agencies require strict sequential numbering without gaps. Cancellation creates a credit note that references the original number rather than reusing it.

What is the difference between invoice and receipt? An invoice is a request for payment, issued before money changes hands. A receipt is proof that payment was received, issued after. Many systems print both from the same template with a status flag.