EU E-Invoicing for OpenCart

Overview

EU E-Invoicing turns your OpenCart invoices into structured e-invoices. Every order invoice gets an EN 16931 e-invoice with the same number as the OpenCart invoice, and every refund or return an e-credit note, in four formats:

• ZUGFeRD / Factur-X (EN 16931 profile): a PDF/A-3 that people read like any invoice, with the factur-x.xml data file inside for accounting software
• XRechnung 3.0 CII and XRechnung 3.0 UBL: the German format for public buyers and B2B, with the buyer reference (Leitweg-ID)
• Peppol BIS Billing 3.0 UBL: for your Peppol access point

What it does

• Same number as OpenCart. The e-invoice carries the OpenCart invoice number (prefix + number). It is created when an order reaches the statuses you choose, or with one click on the order page; the order gets its OpenCart invoice number if it has none.
• Kept in step. When an order is edited after invoicing, the e-invoice is built again with the same number and date.
• E-credit notes for refunds (an order status such as Refunded), returns (a return status with the action Credit Issued or Refunded) and partial credits on the order page (quantities, shipping and fees, an extra amount). Every credit note references its invoice.
• Business buyers. VAT ID, buyer reference / Leitweg-ID, Peppol ID and purchase order number as OpenCart checkout fields (created in one click), editable on the order page. With our EU VAT Number Validation installed, its checked VAT number is used.
• VAT from your tax rules. The rate of every line is rebuilt from the OpenCart tax classes and checked against the tax stored on the order. Categories S, Z, E, AE, K, G and O: intra-community supply or reverse charge for EU business buyers without VAT, exports outside the EU, exempt tax classes. Coupons and reward points become allowances per VAT group; shipping, handling and low order fees become charges; gift vouchers and store credit count as paid. Amounts in the order currency.
• Validation of every document in every format with the EN 16931, XRechnung and Peppol rules, with plain messages on the order page. Optional: send XRechnung files to your own KoSIT validator service.
• Delivery. E-mail to the customer with the files you choose attached; downloads on the order page of the customer account; signed links. ZIP export of a selection or a filter, in one format or all.
• Payment means from the payment method: bank transfer with your IBAN (also read from the Bank Transfer instructions), cash on delivery, cheque, online payment; a mapping per payment method.
• Events only, no OCMOD, no core edits, no external service. One licence for OpenCart 4 and 3.

The extension writes files in these standard formats. Whether a document meets the invoicing rules of your country depends on your data and settings: check them with your tax adviser.

Installation

Requirements

• OpenCart 4.0.2.0 to 4.1.x, or 3.0.3.8 to 3.0.5.x (tested on 4.1.0.4 and 3.0.5.1)
• PHP 7.4 or newer with mbstring and zlib (OpenCart needs them anyway); cURL only for the optional KoSIT validator service
• Working store e-mail (System > Settings > Mail) if customers should get their e-invoices by e-mail

Install on OpenCart 4

1. Go to Extensions > Installer and upload kv_eu_einvoicing.ocmod.zip.
2. Press the install button next to EU E-Invoicing.
3. Go to Extensions > Extensions, choose Modules and install EU E-Invoicing.

Install on OpenCart 3

1. Go to Extensions > Installer and upload kv_eu_einvoicing-oc3.ocmod.zip.
2. Go to Extensions > Modifications and press Refresh.
3. Go to Extensions > Extensions, choose Modules and install EU E-Invoicing.

First steps

1. Open Sales > E-invoices > Settings (or the module in Extensions > Modules).
2. Seller: legal name, street, postal code, city, country, VAT ID (or tax number), phone and e-mail for questions, IBAN for bank transfer, optionally your Peppol ID.
3. Documents: check the order statuses that create e-invoices and e-credit notes. The installation picks Processing, Processed and your complete statuses for e-invoices, Refunded, Reversed, Chargeback and Voided for credit notes, and returns with the status Complete and the action Credit Issued or Refunded.
4. Buyer fields: press Create the ticked fields to add VAT ID, buyer reference / Leitweg-ID and Peppol ID to registration, checkout and the address book.
5. VAT and payment: check the category for untaxed EU business sales (K for goods, AE for services) and the payment means of your payment methods.
6. The Overview shows a set-up check. Open an order and its E-invoice tab to create the first e-invoice.

Updating

Upload the new package the same way. Documents and settings stay; tables and settings are brought up to date the next time you open the extension.

Removing

Uninstalling removes the events and settings. The e-invoices, e-credit notes and buyer data stay in the database (invoices must be kept for years) and are back when you install again. To delete them too, switch on Settings > Data > Delete all e-invoices, e-credit notes and buyer data first.

Configuration

All settings are on Sales > E-invoices > Settings.

Seller

Your company as it appears in every e-invoice: legal and trading name, address, VAT ID or tax number, company registration ID and scheme, legal information (court, capital), a contact with phone and e-mail (XRechnung requires both), your Peppol ID (scheme + identifier; empty: derived from the VAT ID for Peppol, your e-mail for XRechnung), bank account (empty: read from the Bank Transfer payment instructions when they contain an IBAN) and payment terms.

Documents

• Status: off stops automatic e-invoices, e-mails and customer downloads; existing documents stay.
• Formats and main format: each document is available in every enabled format; the validation result of the main format is the status of the document.
• Automatic e-invoices at the chosen order statuses; Business buyers only limits them to orders with a company, VAT ID, buyer reference or Peppol ID.
• Invoice number: give the order its OpenCart invoice number when it has none (the same way as the Generate button of the order page).
• Paid at these statuses: such orders show "Paid in full" and no amount due; other orders get a due date after the chosen number of days.
• Buyer reference: the order ID when the buyer gives none (XRechnung and Peppol need one).
• Credit note at these order statuses and for returns (return status + return action).
• Credit note numbers: format with {YYYY} {YY} {MM} {N} and the digits of {N}.
• A note on every document; optionally the customer comment of the order.

VAT and payment

• Lines without VAT: Z (zero rated), E (exempt) or O (not subject to VAT, for example small businesses).
• EU business buyers: K (intra-community supply of goods) or AE (reverse charge for services) for untaxed orders of buyers in another EU country with a VAT ID.
• Exports: untaxed orders shipped outside the EU become category G.
• Exemption reason printed for category E.
• Category per tax class for tax classes whose 0 % lines are exempt or not subject to VAT.
• Payment means per payment method (automatic: bank transfer = SEPA credit transfer, cash on delivery = cash, cheque, others = online payment service).
• Unit of quantities and the number format of the PDF.

Buyer fields

Choose the OpenCart custom fields that hold the VAT ID, buyer reference / Leitweg-ID, Peppol ID (entered as scheme:identifier, for example 0088:4012345000009) and purchase order number, or create them in one click. Edit names, customer groups and order in Customers > Custom Fields.

Delivery

E-mails for new e-invoices and e-credit notes with the attached formats, a copy address for your bookkeeping, and the formats customers can download in their account.

Validation service

Optional. Run the official KoSIT validator with the XRechnung configuration in daemon mode on a computer you control, for example java -jar validator.jar -s scenarios.xml -r config -D -H 127.0.0.1 -P 8080 in the folder of the configuration.

Enter its address (for example http://127.0.0.1:8080/), press Test with a sample, and optionally check every new document automatically. Only XRechnung files are sent, only to this address.

Data

Delete all e-invoices, e-credit notes and buyer data when uninstalling: off by default.

Usage

Every day

Nothing to do. When an order reaches one of the chosen statuses, its e-invoice is created with the OpenCart invoice number and e-mailed to the customer with the files you chose. A refund status creates an e-credit note for everything still open; a completed return with the action Credit Issued or Refunded creates one for the returned quantity.

The E-invoice tab of the order page

Sales > Orders > (order) > E-invoice:

• Buyer: name, type (business or consumer), VAT ID, buyer reference, Peppol ID, purchase order number and invoice number. Edit buyer data changes them for this order and rebuilds the e-invoice (same number and date).
• Create e-invoice (or Create invoice number and e-invoice when the order has none yet).
• Every document with number, date, total, VAT and validation status; a download button per format (a red ! marks a format with errors); Validation details with the rule and a plain message; Rebuild; E-mail to customer; Check with KoSIT when a validator service is set.
• Create a credit note: quantities per product, shipping and fees, an extra amount with VAT and a reason; or Credit everything open. Discounts follow the credited lines in proportion. This does not refund the payment.

Sales > E-invoices

All e-invoices and e-credit notes with search (number, buyer, VAT ID, order) and filters (type, validation, dates), downloads per row, ZIP of the selected documents (or of everything that matches the filter) in one format or in all, and Rebuild selected. Send the ZIP to your accountant or upload it to your e-invoicing platform or Peppol access point.

Customers

Signed-in customers find their e-invoices on the order page of their account (formats chosen in Delivery). The links in the e-mail work without signing in; they are signed and never open another order.

FAQ

Which standards are supported?

EN 16931 in four syntaxes: ZUGFeRD / Factur-X (EN 16931 profile, PDF/A-3), XRechnung 3.0 CII and UBL, and Peppol BIS Billing 3.0 UBL. In our tests the generated files pass the official KoSIT validator with the XRechnung configuration, the Peppol BIS 3.0 schematron, the EN 16931 CII schematron and veraPDF (PDF/A-3) through Mustang.

Does it make my invoices legally compliant?

It writes the files in these formats from your order data and settings and checks them with the rules of the standards. Whether an invoice meets the rules of your country also depends on your data, settings and processes: ask your tax adviser.

Does it send e-invoices to the Peppol network?

No. It creates the files; upload them to your Peppol access point or e-invoicing platform (single files or a ZIP).

Which invoice number does the e-invoice get?

The OpenCart invoice number of the order (prefix + number), the same as the invoice print. Orders without one get it the same way as the Generate button does. E-credit notes have their own series.

What happens when I edit an order after invoicing?

The e-invoice is built again with the same number and date. E-credit notes keep their content.

How are VAT rates found?

OpenCart stores the tax amount on each order line. The extension rebuilds the rate from the product's tax class and your tax rules for the order's address and customer group and checks it against that amount; when the tax set-up changed after the order, the rate comes from the stored amounts and the order page shows a note.

Can buyers enter their VAT ID?

Yes, as an OpenCart custom field (created in the settings). Our EU VAT Number Validation is used when installed.

Does the Peppol format work for consumers?

Peppol is for business buyers with a Peppol ID or VAT ID. Consumer invoices show a validation error for that format; use the PDF or XRechnung for them.

Does it send data to an external service?

No. Files are made on your server. Only if you enter the address of your own KoSIT validator service are XRechnung files posted there.

Which languages?

Document labels are in English; names and addresses in Latin, Greek and Cyrillic scripts print correctly in the PDF.

Does it use OCMOD?

No. Events only, no core file edits.