Create and send Lexware Office invoices from a list

1. Click the + symbol in the main menu and choose Rechnung erstellen, or open the Belegliste and choose Neuer Beleg > Rechnung.
2. Pick the customer in the Kunde field or create one, check the invoice date and the payment terms, and enter the delivery date if needed.
3. Add each line with + Artikel, or as a free-text line, set quantity and price, and click Weiter zur Vorschau to check the PDF layout.
4. Click Abschließen und Speichern, which assigns the final invoice number and shows the document in the list as Offen; Lexware Office does not allow editing a finalised invoice.
5. Click Per E-Mail senden to send it from your own sender address with an email text template, and repeat for every customer on the list.

Here is this month's billing list. For each customer, create the invoice in Lexware Office with the hours and rate I gave, check the totals against the list, finalise it and send it by email. Add customers that do not exist yet.

1. 01

   Match each line to a contact

   Your agent calls list_contacts for every name in the list and matches on customer number or exact name. A name with no match is created with create_contact only when your prompt says to, otherwise it is reported and skipped.

2. 02

   Save a draft and check the totals

   create_invoice saves the invoice with the dates and lines you gave. The agent compares the net and gross totals to your list before anything is final, because a finalised invoice cannot be edited any more.

3. 03

   Finalise only what matches

   finalize_document runs for drafts whose total equals the list. A mismatch stays a draft, so you can fix it in Lexware Office, and shows up in the report with both amounts.

4. 04

   Send to the contact's email

   send_document uses the email address saved on the contact. A contact without one is left finalised but unsent, and the agent names it so you can add the address.

5. 05

   Report numbers and gaps

   The run ends with the invoice numbers Lexware Office assigned, the sum of all sent invoices and every contact or line that was skipped. Finalising and sending wait for your OK by default until you switch confirmation off.

Billing list: 6 customers
Finalised and sent 5 invoices, e.g. RE1043 Nordlicht Design GmbH: 1,130.50 EUR gross
New contact created: 1 (Studio Fjord)
Left as draft 1: Becker Consulting, list says 2,400.00 EUR, draft totals 2,380.00 EUR
No email on file: 0

curl -X POST https://cotlet.dev/api/v1/lexware-office/contacts/c_4f2a91/invoices \
  -H "Authorization: Bearer $COTLET_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"invoice_date":"2026-10-14","payment_term_days":14,"lines":[{"name":"Consulting, October","quantity":10,"unit_price_net":95,"tax_rate":19}]}'

{
  "document_id": "d_c44e19",
  "type": "invoice",
  "number": null,
  "status": "draft",
  "contact": {
    "contact_id": "c_4f2a91",
    "name": "Nordlicht Design GmbH"
  },
  "date": "2026-10-14",
  "due_date": "2026-10-28",
  "lines": [
    {
      "name": "Consulting, October",
      "quantity": 10,
      "unit_price_net": 95,
      "tax_rate": 19
    }
  ],
  "total_net": 950,
  "total_tax": 180.5,
  "total_gross": 1130.5,
  "currency": "EUR"
}

MCP: add https://cotlet.dev/mcp/v1 with the same key; the call is lexware_office_write → create_invoice. Example data.

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