Data acquisition protocol

The data entry protocol (DEP) is a continuous, tamper-proof file that records all cash register transactions. Every transaction that is processed via a cash register (e.g. cash sale, reversal, refund) is recorded in the DEP. This log must be able to be read and checked by the tax authorities at any time.

The DEP not only contains the transaction data itself, but also the digital signature of each transaction, which ensures that the data is unchanged and complete.

Each entry in the DEP contains several important pieces of information that ensure that the data is both traceable and tamper-proof. This data includes:

Consecutive transaction number

Each transaction is given a unique number that is assigned consecutively. This ensures complete documentation of the sequence of business transactions.

Timestamp of the transaction

The exact time at which the transaction took place is recorded in the minutes.

Gross amount of the transaction

The amount of the respective transaction, including taxes, is recognized.

Signature of the transaction

Each transaction is provided with a digital signature by the signature creation device (SEE). This signature is stored in the DEP and ensures that subsequent changes to the transaction are recognizable.

Linking of transactions

Each new transaction in the DEP contains the hash value of the previous transaction. This chaining makes the DEP tamper-proof, as any change to a previous transaction would break the chain and be easily recognizable.

Further transaction information

This includes specific information on tax classes, reversals, refunds or other special transactions.

The data entry protocol is subject to strict retention obligations. According to the RKSV, the DEP data must be stored for seven years in an audit-proof manner so that it is available at all times in the event of a tax audit.

There are two requirements for storing the DEP:

Secure storage

The DEP must be stored in a tamper-proof (audit-proof) manner. This means that the POS system must store the DEP continuously and protect it against data loss or unauthorized changes.

Provision in the event of an audit

At the request of the tax authority, the DEP must be provided by the taxpayer as a data export (in the specified JSON format).