A good scanner is best suited for digitizing paper documents. A resolution of 300 dpi when scanning is sufficient to save the document in printable form. This ensures that the content of the document remains clearly legible even after it has been printed out on an office printer. Suitable file formats for digital storage are PDF, PNG, JPEG or TIFF. It should not be possible to change the documents after they have been saved. Therefore, formats such as doc, odt- or xls are not suitable for GoBD-compliant documents. After scanning, the scanner should save the document directly into the filing system or forward it as an e-mail.