Usage

The order flow

1. A customer orders. The order reaches the status you chose in the settings (default Paid).
2. The add-on queues the invoice. At the next cron run it checks whether a contact is needed, builds the invoice from the order (products, shipping, payment fee, order discount, tax per line) and creates it in Lexware Office with the finalize option. Lexware Office assigns the invoice number.
3. The order gets a Lexware Office tab: invoice number, status in Lexware Office, total, open amount, paid date, tax type, e-invoice format, the credit notes, and buttons to download the PDF, open the invoice in Lexware Office and refresh the payment state.
4. When the customer pays (in your payment provider or when you book the payment in Lexware Office), Lexware Office calls the store and the add-on reads the payment state back. The order tab shows Paid; with the setting “Set the order status when the invoice is paid” an open order moves on.
5. A refund (the order reaches the refund status) or a completed return creates the credit note in Lexware Office, linked to the invoice. Lexware Office allows only one credit note per invoice (partial or full amount): the first credit is created, and any further credit for the same invoice is logged as a warning (Jobs / log) because it cannot be sent; create it in Lexware Office by hand.

The add-on never books payments in Lexware Office: the Public API only reads payments. Book incoming payments in Lexware Office (bank import or by hand).

Business customers and tax

• A buyer with a company name or a VAT ID becomes a customer contact in Lexware Office (found by e-mail and name first, so an existing contact is reused). The invoice references the contact and prints the billing address of the order.
• Consumers get a one-time address on the invoice unless “Create a contact for consumers” is on.
• Sales to another EU country: a company with a VAT ID and no VAT charged is invoiced as intra-community supply; a consumer with VAT charged is a distance sale when your Lexware Office account uses the DESTINATION principle.
• Sales to a third country without VAT are invoiced as export delivery.
• A small business account (section 19 UStG) issues vat-free invoices only.
• Lexware Office decides what a valid combination is; if it refuses the invoice (for example a rate it does not accept) the job stops with its message in the log and on the order tab. Fix the cause (Tax rates page, contact data) and press Create invoice now.

E-invoices (XRechnung and ZUGFeRD)

Lexware Office creates the e-invoice. For a customer contact that has a Leitweg-ID (set in Lexware Office), the invoice becomes an XRechnung; the add-on reads the electronicDocumentProfile of the invoice and shows it on the order tab. For an XRechnung the tab offers the XML file (the PDF of an XRechnung is only a preview and not a valid e-invoice, as the Lexware Office documentation says); customers see the XML link on their order page. A ZUGFeRD invoice is a PDF with the data embedded. The add-on does not create Leitweg-ID contacts and makes no statement about whether an invoice meets a legal format: check that in Lexware Office.

Why this matters in Germany

Since 1 January 2025 every business in Germany must be able to receive and process e-invoices in a structured format for domestic B2B supplies. The duty to issue them follows in steps: until 31 December 2026 paper and other formats are still possible (electronic formats with the recipient’s consent); for supplies made in 2027 paper or PDF invoices remain possible only for businesses whose total turnover of the previous year was at most 800,000 euro; from 1 January 2028 the duty to issue applies to all domestic B2B supplies. Source: section 27 paragraph 38 of the Umsatzsteuergesetz (https://www.gesetze-im-internet.de/ustg_1980/__27.html, text checked 2026-11-07) and the letters of the Federal Ministry of Finance of 15 October 2024 and 15 October 2025 on the introduction of the mandatory e-invoice, with the ministry’s FAQ at https://www.bundesfinanzministerium.de/Content/DE/FAQ/e-rechnung.html (the ministry’s pages were not readable by script at the time of writing; read them there). Invoices to consumers are not affected. This add-on is an invoicing connector, not tax advice; ask your tax adviser which rules apply to your business.

Pages

Page	What it is for
Orders > Lexware Office documents	All invoices and credit notes with number, total, status, errors. Filter by kind and state; Queue past orders (administrator)
Connection	API key, test, Lexware Office account details, event subscriptions
Tax rates	Percentage per CS-Cart tax, shipping rate
Log	Every action and error, masked; CSV export
Jobs	The queue: counts, retry, remove, run now (administrator)

Common tasks

• Create an invoice for one order now: open the order, tab Lexware Office, Create invoice now.
• Create a credit note by hand: Create credit note on the order tab (it credits what is left on the invoice; refused when the invoice has a credit note already).
• Refresh the payment state: Refresh payment state.
• Invoice old orders: set “Do not sync orders before” (required, the button refuses without it), then Queue past orders. A finalized invoice cannot be deleted through the Lexware Office API, so after uninstalling and reinstalling the add-on (its document list is empty again) set the date to the day of the reinstall before you queue past orders.