Technical details and characteristics

Features Requirements for a cash register 

The RKSV regulates the technical details for security services in the cash register.  Here is an overview of the requirements for the cash register: 

• Data collection protocol 
• Printer for the creation or device for the electronic transmission of payment receipt 
• Interface to a security service with a signature creation unit
    (A signature creation unit can also be connected to multiple cash registers) 
• Encryption algorithm AES 256 
• Unique cash identification number within the company 
• The cash register shall not contain any devices which can be used to avoid the control of the safety device. 
• The use of a cash register by several companies is only permitted if each one can use a certificate assigned to it and a separate data collection protocol can be kept per company.

Each cash register must keep a data collection protocol. In it, every single cash turnover is to be recorded and stored. For each cash turnover, the prescribed receipt data must be documented. Training and cancellation bookings must also be recorded and stored in the data collection protocol, as well as cash transactions. The data in the protocol are at least quarterly on an electronic external medium unchangeably safe and removable. The contents of the machine-readable code of the cash transactions must be documented together with the associated cash transactions in the log of the cash register. From 1 April 2017, the data collection protocol of a cash register must be able to be exported at any time to an external data carrier in export format (according to the RKSV regulation). 

The sum memory serves to continuously sum up the recorded cash turnover in the cash register (turnover counter). Training bookings must not affect the sales counter. At the end of each month, the intermediate balances of the turnover counter must be determined (monthly counter). At the end of the calendar year, the monthly receipt containing the meter reading at the end of the year (annual receipt) must be printed out, checked and kept for seven years. The exact procedure at the end of the month and the end of the year are regulated in the chapter total storage in the RKSV.   

Commissioning of the signature or Seal creation unit (SEE) 

The commissioning of the safety sevice for the cash register consists of the initialization (conversion) of the cash register and the preparation and verification of the start receipt. The registration of the signature or seal creation unit and cash register via FinanzOnline as well as the examination of the start-up receipt must be completed at the latest one week after the commissioning of the security service. The start receipt is tested by means of a test app in the form of a mobile version (e.g. smartphone) or in the form of a web service.  

Requirements for the signature or seal creation unit 

Every single cash turnover and monthly, annual and final receipt as well as every training and cancellation booking must be signed electronically. In order to ensure manipulation protection, electronic signatures or seals must be able to be requested and taken over by the cash register. This must be done via a suitable interface to the signature or seal creation unit. 

In the creation of signatures or seals, the following data must be included: 

• Cash register identification number 
• Sequential number of cash turnover 
• Date and time of the receipt providing 
• Amount of cash payment separated by tax rates 
• With the encryption algorithm AES 256 encrypted status of the sales counter 
• Serial number of the signature or seal certificate 
• Signature or seal value of the previous cash turnover of the data collection protocol (concatenation value) 

Further details can be found in the appendix of the RKSV. After determining each signature or seal value, the cash register has to prepare a machine-readable code for the document creation and storage in the data collection protocol.

This code must contain the same data as for the creation of signatures or seals and, in addition, the signature or seal value of the cash turnover. Training and cancellation bookings must also include the designation "training booking" or "cancellation booking" in the machine-readable code. The requirements for the SEE are regulated in Annex II of the eIDAS Regulation. Entrepreneurs must purchase the required number of SEE from a trusted service provider established in the EU/EEA area or in Switzerland that offers qualified signature or seal certificates. The costs for the procurement of the signature/seal creation units are borne by the entrepreneur. 

Via FinanzOnline the purchased signature/seal creation units have to be reported. In the event of decommissioning or failure of the signature/seals creation units, a report must be made via FinanzOnline. The BMF maintains a database of the signature/seal creation units including the messages. 

On request (financial police, external auditor), a cash turnover with zero amount must be created. The data collection protocol must be transferred to a data carrier provided by the company for the specified period of time.