Use the AdditionalDocumentReference to model this information. This element is required if you attach a file.

Elements

Element	Description
`Invoice/AdditionalDocumentReference/ID`	You must use a unique name for the file.
`Invoice/AdditionalDocumentReference/DocumentDescription`	Specify a description .
`Invoice/AdditionalDocumentReference/Attachment/EmbeddedDocumentBinaryObject`	The attachment coded in Base 64.
`Invoice/AdditionalDocumentReference/Attachment/EmbeddedDocumentBinaryObject [mimeCode]`	Specify the type of file. For example, `application/pdf` for a PDF.
`Invoice/AdditionalDocumentReference/Attachment/EmbeddedDocumentBinaryObject [filename]`	Specify the name of the files.

Example

<ubl:Invoice>
    <!-- Code omitted for clarity -->
    <cac:AdditionalDocumentReference>
        <cbc:ID>01_15_Anhang_01.pdf</cbc:ID>
        <cbc:DocumentDescription>Aufschlüsselung der einzelnen Leistungspositionen</cbc:DocumentDescription>
        <cac:Attachment>
            <cbc:EmbeddedDocumentBinaryObject mimeCode="application/pdf" filename="01_15_Anhang_01.pdf">JVBERi0xLjUNCiW1tbW1DQoxIDAgb2JqDQo8PC9UeXB...</cbc:EmbeddedDocumentBinaryObject>
        </cac:Attachment>
    </cac:AdditionalDocumentReference>
    <!-- Code omitted for clarity -->
</ubl:Invoice>