cashwerk and Lexware: sales here, accounting there
cashwerk is not an accounting system and does not want to be one. Lexware stays the accounting, cashwerk delivers everything before it: customer, deal, project, time, invoice.
The sync covers contacts, companies, invoices, credit notes and payments. Contacts and companies run both ways. An invoice from cashwerk appears as a document in Lexware, and a payment booked there comes back to the invoice. Offers stay in cashwerk. Lexware reports changes to contacts, invoices and credit notes by webhook; cashwerk pulls payments on a schedule. Open items and dunning in cashwerk therefore work with the state of your bookkeeping.
A sync must not overwrite what is yours. Internal customer and invoice numbers stay untouched, and contacts and companies follow fixed field rules. Every run is in the sync log with status and error list. If sign-in failures pile up, cashwerk deactivates the connection and shows it in the portal, instead of collecting errors.
The connection belongs to the workspace, not to a single user, and is included in the Business plan. You set it up in the integrations portal: sign in with Lexware, allow access, choose objects and direction, follow the first sync. Whatever Lexware does not cover, you reach through the REST API, webhooks, the n8n node or the MCP server.
