Electronic invoices must be stored in the original format, regardless of whether the storage takes place in the productive system, in the archive system, or by outsourcing to another DP system. In most cases, the invoice is sent by e-mail in the form of a structured PDF file. The document should be archived immediately after receipt to prevent loss or manipulation.
If changes need to be made to the document after the fact, the original content of the invoice and documentation of the changes must still be evident. If the invoice needs to be converted to an in-house format, both files must be linked and retained to ensure authenticity and integrity.
If e-invoices are transformed into another format upon receipt, both variants must be archived despite this, the original document and the converted document. Even with a hybrid format, both parts of the invoice must be backed up. When converting a paper invoice into a digital format, it is permitted in Germany to dispose of the original, i.e. the paper invoice, if the process that takes place to digitize the invoice is recorded accordingly.