

Dashboard: invoiced revenue, open and overdue invoices, expenses and your Kleinunternehmer limit at a glance.
Heute Kleinunternehmer, morgen mit Umsatzsteuer — KleinBooks wächst mit.
KleinBooks brings the German business workflow — Angebot Rechnung (quote invoice) — directly into your own WordPress admin. No second tool, no monthly SaaS subscription. Start as a Kleinunternehmer (§19 UStG); when your business passes the €25,000 limit, switch to Regelbesteuerung (standard VAT) with one confirmed click and keep working in the same tool.
KleinBooks Pro (€69 / year incl. 19% German VAT, i.e. €57.98 net; the VAT follows your country, businesses with a VAT ID pay net; 14-day free trial without credit card that ends automatically) is a separate paid version that adds the bookkeeping side. It is sold by our authorised reseller (Merchant of Record) Freemius, Inc.:
The free version is an invoicing tool: sent invoices stay editable. GoBD lock with Storno is part of KleinBooks Pro.
The admin app is built with React (@wordpress/scripts). The full unminified source for the compiled bundle in assets/, together with build instructions, is included in the plugin’s src/ directory.