How shall we keep and store electronic invoices?

How to keep e-invoices?

According to currently effective legal regulations, electronic invoices have to be preserved in their original form using a method which ensures immediate retrieval and constant readability of all data of the accounting document and excludes the possibility of subsequent manipulation.

This means that electronically issued invoices may not be preserved in any other form (e.g. printed out). Tax related obligations and rights are always certified by the form of the invoice at the time of its issuing. The taxpayer obliged to keep electronically issued invoices is responsible for the preserving of the invoices in compliance with the relevant regulations and the consequences of non-compliance also burden this taxpayer. This does not mean that the taxpayer will have to arrange the keeping of the invoices himself; he may also use a service for this purpose.

Throughout the keeping of the invoices, the taxpayer must ensure the

1. integrity,
2. authenticity and
3. readability

of the documents and the data included in the documents

The person obliged to keep electronic invoices must continuously ensure during the term of this obligation that the method of keeping of the electronic document excludes the possibility of subsequent manipulation and protects the electronic documents from deletion, destruction (whether intended or unintended),damage and unauthorized access. The person obliged to keep e-invoices must also ensure that the electronic documents are suitable for interpretation (are readable) during the term of the preservation obligation – through the provision of the software and hardware environment required for the display of the documents. During the keeping of these documents, it has to be taken into account whether the electronically issued invoices qualify as

1. electronic data with an electronic signature and time seal or
2. an electronic invoice prepared using an EDI system.

There are three options for the keeping of electronic invoices with an electronic signature and time seal:

1. The person obliged to keep the invoices commissions an archiving service provider meeting the relevant requirements for the keeping of the documents. The operation of archiving service providers is regulated in detail in Eat. (Act XXXV of 2001 on Electronic Signature) and the decrees on the execution of this act and audited regularly by the National Media and Infocommunications Authority.
2. He preserves the invoices himself.
3. He commissions another person – not an archiving service provider as defined in Eat. – for the keeping of the invoices. In this case the person having the preservation obligation and the service provider regulate the services to be provided and the liability assumed by the service provider in a service contract.

In cases 2. and 3. above, the person keeping the documents is responsible for checking the validity of the electronic signature and the time seal on the invoices. In addition, if the term of the preservation obligation is longer than 11 years from the placement of the electronic signature on the document, the person having the preservation obligation

1. is responsible for obtaining and keeping the information necessary for the long-term validation of the electronic signature (the validity chain),
2. must have a time seal issued by a service provider qualified under Eat. placed on the validity chain,
3. must repeat the placement of the time seal specified in point b. if the cryptographic algorithm of the earlier time seal defined in point b. is no longer safe according to the provisions of Eat.

If electronic signatures and time seals were placed on a number of electronically issued invoices, these invoices have to be managed jointly during the period of keeping. As explained above, electronically issued invoices may be archived by both the issuer of the invoice or the (archiving) service provider commissioned by the issuer. Archiving services are typically provided by authentication service providers.