create-invoice

Help the user create and send an invoice step by step:

1. Identify the client: If a client name is provided in $ARGUMENTS, call list_clients and find the matching client. If ambiguous, ask the user to clarify. If no client exists, offer to create one with create_client.
2. Gather invoice details: Collect the following information (ask for anything not provided):
   • Line items: description, quantity, unit price, VAT rate (DE: default 19% / PL: default 23%)
   • Invoice date (default: today)
   • Due date / payment terms (default: 14 days)
   • Any notes or special terms
3. Create the invoice: Call create_invoice with all gathered details. Use the correct client_id from step 1.
4. Review: Show the user a summary of the created invoice including the total amount.
5. Send: Ask the user if they want to send the invoice now. If yes, call send_invoice to email it to the client. Omit subject and body to use the company's email template; pass additional_emails for CC recipients.

Important:

• Use the company's default currency unless the user names another.
• Default VAT rates: DE: 19% (7% for reduced rate items like food, books) / PL: 23% (8% or 5% reduced rates)
• Invoice numbers are auto-generated by Norman
• For recurring work, suggest create_recurring_invoice instead

Invoice appearance and edits:

• Read get_invoice_settings for the company logo and saved defaults. Pass the saved language/currency when the user does not choose others.
• If the user wants a different design, call list_invoice_templates. Show the available choices and plan access. Do not invent template IDs or bypass paid access.
• Both invoice creation tools accept document_design: template, version, logo size (25–100), text size, spacing and table borders. Use font and color_schema for the font and colour. Omit these three options to preserve company branding. A partial design takes the chosen template's defaults.
• Use update_invoice for invoice/quote edits and update_recurring_invoice for schedule edits. Send only changed fields in changes. Keep existing line IDs when editing items. A partial document design keeps the document's other saved controls; changing its template starts from that template's defaults. Explicit false, zero, blank strings and valid nulls are different from omitted fields.
• Use update_invoice_settings only when the user wants to change future document defaults. Existing documents keep their saved design. Show-customer-number, show-contact-person, QR codes and online payment defaults are included.
• Item rates use minor currency units (cents for EUR), including when copying a catalog product. The API calculates totals. Items also support description, unit, product/category IDs and line discounts.
• For services, provide the requested service start/end dates. For goods, provide the delivery date. A recurring invoice takes interval, interval_count, starts_on (the first invoice date), payment_due_days and billing_in_advance; Norman sets the dates of each invoice from them.
• Creation and edits accept payment links, QR codes, bank details, discounts, VAT notes, recipient/sender snapshots, and email/reminder settings. Use an empty VAT note only when the user requests no note; omission lets the API choose it.
• In Germany, issuing an invoice books it at once: a GmbH/UG books the revenue on the service date, the self-employed count it when the payment comes. The invoice's payment takes that booking over.
• Payment reminders are off unless the user asks for them. auto_reminders / autoReminders true on create_invoice, create_recurring_invoice or update_invoice makes Norman remind the client by the company's rule (paid plans). settings_on_overdue is an older field and sends nothing.
• list_invoice_emails shows every email to the client with its delivery status. Email wording lives in list_invoice_email_templates / save_invoice_email_template; the reminder rule in get_invoice_email_settings / update_invoice_email_settings.
• Set is_to_send / isToSend only when sending is requested or already authorized. Otherwise save the document without sending it. The same applies to mode "send" on a recurring invoice; the default "draft" sends nothing.

Corrections and delivery notes (documents made from an existing document):

• To reverse an issued invoice in full, call cancel_invoice with the invoice id. Norman writes the Stornorechnung with the same lines, the next invoice number and a reference to the invoice, and marks the invoice cancelled. Confirm with the user first: a cancellation is a numbered document the client receives, not an edit. A draft, an issued or an overdue invoice is edited with update_invoice. A paid invoice cannot be edited: correct it with cancel_invoice or create_credit_note.
• To correct part of an invoice (a wrong quantity, a price reduction, returned goods), call create_credit_note with the invoice id and the lines to credit. Without lines the whole invoice is credited. Norman prints "Rechnungskorrektur", never "Gutschrift", because since 2013 that word means self-billing under § 14 UStG. Use status: "draft" when the user wants to review it first.
• Polish companies: a cancellation or a credit note is a faktura korygująca (its PDF says so). For an invoice in KSeF, Norman sends it to KSeF as a correcting invoice (KOR); when it cannot go yet, for example before KSeF accepted the invoice, the API refuses and says why: relay that message.
• Lines on a Stornorechnung or a Rechnungskorrektur are positive, like on the invoice. The PDF prints every amount with a minus, and Norman turns lines typed with a minus around, so never negate amounts yourself.
• To correct an invoice issued outside Norman, call create_invoice with document_type "cancel" or "credit_note" and pass preceding_invoice_number and preceding_invoice_date. The PDF prints "Storno zu Rechnung … vom …" and the e-invoice carries the reference. A correction prints no due date.
• To make a Lieferschein, call create_delivery_note with the invoice id, or the id of a quote the client approved. It prints quantities and units only, no prices, and lands in the company's Files space under "Delivery notes". Pass lines for a partial delivery.
• convert_offer_to_invoice makes a draft invoice from a quote. The quote stays, with the status "invoiced", and the invoice links to it. Issue the invoice with update_invoice (status "saved") before sending it.
• To bill the same thing again, call duplicate_invoice with the invoice or quote id: it makes a draft dated today with the same lines, payment term and bank details. Move the service or delivery dates with update_invoice, then set status "saved" to issue it. A draft is never emailed or matched to a payment.
• Both the PDF and the e-invoice XML name the source document, so never repeat the reference in message.