Automatic Invoices

With the Automatic Invoices addon, Bookicorn creates a legally compliant invoice in ZUGFeRD format for every purchase — without any manual intervention on your part. Customers receive the invoice as a PDF by email, and you can download it at any time in the admin area.

Category: Finance

What are automatic invoices?

An automatic invoice is a document that is created immediately after a successful purchase — without any manual action. Bookicorn handles:

• Sequential, gap-free invoice numbers
• Correct invoice date and due date
• All legally required mandatory details (name, address, tax number, VAT)
• Line items for the purchased item (credits, booking, package)
• ZUGFeRD format for machine readability

Invoices are generated for all purchase transactions in Bookicorn: credit purchases, direct course bookings, and packages.

ZUGFeRD — the German e-invoice format

ZUGFeRD (Zentraler User Guide des Forums elektronische Rechnung Deutschland) is a hybrid invoice format: the PDF file looks normal to human readers, but also contains embedded XML data. This means the invoice can both be read by your tax advisor and automatically processed by accounting software.

Benefits of ZUGFeRD:

• Compatible with DATEV, Lexware, sevDesk, and other common accounting programs
• Meets the requirements of the German e-invoicing mandate (mandatory for B2B invoices from 2025)
• No manual data entry required at the tax advisor — data is recognized automatically
• GoBD-compliant archiving

Note: For public sector clients (B2G), ZUGFeRD has been mandatory since 2020. For the B2B sector, the mandate came into effect on 01.01.2025. With this addon, you are fully covered.

Activation and Setup

Activate the addon

Enter mandatory details

For invoices to be legally valid, you need to enter the following information once:

Tip: Are you a small business owner under §19 UStG? Then enable the Small Business Exemption option — invoices will then be created without VAT and with the legally required notice text.

Automatic creation for every purchase

Once the addon is active and the invoice data is complete, everything runs automatically:

For credit purchases:

• Customer buys a credit package
• Payment is processed via Stripe
• Invoice is created immediately and sent by email

For direct course bookings with payment:

• Booking is completed
• Payment is confirmed
• Invoice is generated automatically

For cancellations and refunds:

• Bookicorn automatically creates a cancellation invoice
• The original invoice remains in the system
• Customers also receive the cancellation invoice by email

Note: Invoices for free courses (€0) are not created, since no payment transaction takes place.

Sequential invoice numbers

Bookicorn assigns invoice numbers automatically in sequential order. The format is configurable:

Set the number format

Under Settings → Invoices → Number Format you can customize the format:

• Prefix: e.g. RE, INV, or your studio abbreviation
• Year: e.g. 2025-
• Sequential number: Starting point selectable (e.g. 0001)

Examples:

RE-2025-0001
INV-2025-0042
YOGA-2025-0128

Important: Invoice numbers must not have gaps and must be unique. Bookicorn ensures this automatically — you don't need to worry about it.

PDF download

In the admin area

You can find all invoices under Finance → Invoices:

• Filter by period, customer, or invoice number
• Click on an invoice to open it
• Download the PDF file
• Export multiple invoices as a ZIP archive

For customers

Customers can download their invoices directly in the Customer Dashboard:

• Open Dashboard → My Purchases
• An invoice icon appears next to each purchase
• One click downloads the PDF

Email delivery to customers

Every invoice is automatically sent to the customer's email address — immediately after payment confirmation.

Contents of the invoice email:

• Subject: Your invoice [invoice number] from [studio name]
• Brief confirmation text
• Invoice as a PDF attachment (ZUGFeRD format)

Customize the email text

Under Settings → Email Templates → Invoice you can customize the text of the invoice email. Available placeholders:

• {{customer_name}} — Customer's name
• {{invoice_number}} — Invoice number
• {{invoice_date}} — Invoice date
• {{amount}} — Total amount
• {{studio_name}} — Your studio name

Tips for optimal use

Involve your tax advisor

Tip: Send your tax advisor a sample ZUGFeRD invoice before going live with the addon. This lets them verify that the format is compatible with their accounting software and helps you avoid any surprises at year-end.

Keep invoice data up to date

• Update your tax number or address in Bookicorn immediately when something changes
• Future invoices will then be issued correctly automatically
• Already created invoices remain unchanged (GoBD compliance)

Archiving

• Invoices are stored permanently in Bookicorn
• For year-end closing, you can export all invoices for a given year as a ZIP file
• GoBD requires a retention period of 10 years — Bookicorn handles the digital archiving

Prepare for year-end closing

Tip: Combine the Invoices addon with the DATEV Export addon to provide your tax advisor not only with PDFs but also with machine-readable booking data. This saves them time — and saves you on accountancy fees.