E-Invoicing Module

Description

The e-Invoicing Module brings compliant e-invoicing into WHMCS. When you create an invoice for an enrolled client, the module transmits it through the Peppol network automatically, no separate platform, no manual export, no XML to assemble yourself.

The module connects your WHMCS instance to a certified Peppol Access Point. WHMCS submits the invoice data; the Access Point converts it to Peppol BIS 3.0 / UBL 2.1, validates it against EN 16931, signs it, resolves the buyer's Peppol ID, and routes it to the recipient's Access Point. You never handle a schema or a validation rule.

What It Does

E-invoicing Peppol transmission

• Automatic conversion of WHMCS invoices into Peppol-compliant UBL 2.1 and delivery through the Peppol Access Point network
• Credit note support, so refunds and adjustments are transmitted as compliant electronic credit notes
• Buyer network lookup - check whether a client is registered and reachable on Peppol before you send
• Tax ID validation on VAT numbers and business identifiers, to reduce rejections before transmission

Control and configuration

• Per-client enrollment: enable or disable e-invoicing for each client from the WHMCS admin area
• Required e-invoicing fields added to the Getting Started Wizard, the addon configuration page, and client profiles
• Alerts for clients who have e-invoicing enabled but incomplete or invalid data

Visibility

• A dedicated e-Invoicing dashboard showing invoice volume, delivery status, failed transmissions, and historical records
• Real-time transmission status - delivered, pending, failed, or needs attention - on each invoice
• Error alerts with retry: correct the issue and resend without leaving WHMCS
• Client portal visibility, so enrolled clients can see e-invoice status and download structured invoice files

Why It Benefits You

• Compliance without a second system. This adds structured, Access-Point-routed invoicing where your invoices are already created, instead of alongside a separate billing tool.
• No format engineering. Peppol BIS 3.0, UBL 2.1, EN 16931 validation, digital signing, and recipient routing are all handled for you. WHMCS submits invoice data and receives status back.
• You choose who's in scope. E-invoicing applies per client, so you enroll only the business customers who need it and leave everything else on your existing flow.
• Failures are visible and fixable. Rejections and failed transmissions surface in the dashboard with status detail and a retry path, rather than going silent after send.
• Cost scales with volume. Monthly tiers priced on invoice count, with defined overage rates — no per-seat or per-entity licensing.

Pricing

Monthly subscription in USD, purchased on WHMCS.com.

You can move to a higher tier as your invoice volume grows.

Requirements

• A valid WHMCS license
• WHMCS 9.0 or later
• An active e-Invoicing module subscription and invoice tier
• Clients receiving e-invoices must be registered Peppol participants able to receive Peppol BIS Billing 3.0

Requirements listed are in addition to the WHMCS default system requirements.

Frequently Asked Questions

What is Peppol e-invoicing?

Peppol is the international network used across the EU to exchange structured electronic invoices between businesses. Instead of emailing a PDF, the invoice is sent as machine-readable data through certified Access Points, so the recipient's accounting system can process it directly. A growing number of EU countries now require it.

Does this make my invoices compliant with the Belgian mandate?

The module transmits structured invoices in Peppol BIS 3.0 / UBL 2.1 through a certified Peppol Access Point, which is the transmission method Belgium's B2B mandate requires. Compliance also depends on your own invoice data being complete and correct, the module flags clients with missing or invalid required fields.

Do I need a separate billing tool or a Peppol account of my own?

No. E-invoicing works inside your existing WHMCS billing workflow, and access to the Peppol network is included with the module. You do not need to select, contract with, or configure an Access Point separately.

Do I have to send e-invoices to every client?

No. You enroll clients individually from the WHMCS admin area. Only enrolled clients have their invoices transmitted via Peppol; everything else continues as it does today.

What happens if an invoice is rejected or fails to transmit?

Failed transmissions appear in the e-Invoicing dashboard with status detail. You can correct the underlying issue and retry the send from within WHMCS.

How do refunds and corrections work?

Peppol does not permit editing a transmitted invoice. Issue a credit note instead - the module transmits compliant electronic credit notes referencing the original invoice.

What if my client isn't on the Peppol network?

Use the buyer network lookup to check before sending. A client who is not a reachable Peppol participant cannot receive an invoice over the network.

Can I change tiers later?

Yes. You can upgrade to a higher invoice tier as your volume grows. Overage rates apply to invoices sent above your tier's included volume.

Which countries are supported?

Belgium is the launch market. A Global launch will follow soon.