The default tax rate (eg 23%) is automatically set for invoices you create yourself with the "Add new invoice" option.
You can configure the default tax rate in the Invoices -> Taxes menu.
The default tax rate for accommodation services (e.g. 8%) is automatically set for invoices created in the reservation form in the "Issue an invoice" option.
You can configure the default service rate for accommodation services in the Price list -> Additional services menu.
