Just discovered, that is possible to press “New” and apply a tax code, even the “Apply Tax” is not selected. This allows us to add a calculated tax code.

Problem solved.

An advance invoice is a document issued by a supplier to request payment for goods or services before they are delivered or rendered. This is typically done in situations where the supplier requires payment upfront to cover costs associated with producing or acquiring the goods or services.

Hi,

@Grkoer, we actually have two types of advance invoices in the system, used depending on local legislation: advance invoice (issued as demand for advance/down payment) and prepayment-based invoice, issued to document reception of the advance (i.e. after payment is received).But it does not change anything in this case.

From tax point of view, Calculated tax should only be used on supplier invoices, as it supports reverse charge case - tax is calculated by recipient of the invoice (reported as received and disbursed in the same transaction).
On customer invoice, tax applied should be “real” ( i.e. VAT type)  typically zero % in case of delivery of goods or services to another country, and we can use different code for goods and different for services.