What it means
When an attachment is embedded in the invoice itself (BT-125), the element that holds it must have a mimeCode attribute (BT-125-1). The rule only checks that the attribute is there. A separate rule checks that its value is one of the allowed file types, such as PDF, PNG, JPEG, CSV, XLSX or ODS.
Why it matters
Without the MIME code, the recipient's system cannot tell what the embedded data is, so it cannot open, show or safely handle it. The file does not meet the format, and the invoice is rejected.
How to fix it
In your invoicing software, open the invoice attachments and check that each file is attached normally, because the software usually sets the file type itself. A gap usually means the file was added by a custom export or a script. If you build the XML yourself, add the mimeCode attribute to the AttachmentBinaryObject element, for example application/pdf. If you do not need the attachment, remove it.
The rule as published
Attached document Mime code (BT-125-1) shall be provided. Business terms: BT-125
Where this rule applies
| Rule set | Version |
|---|---|
| EN 16931 (CII) | 1.3.17 |
| XRechnung 3.0 (CII) | 3.0.2 |
| France CTC (CII) | 1.4.0-04 |
Check your file
Drop your e-invoice to see whether CII-DT-105 still fails, and which other rules do.
Related rules
- BR-DEX-01 Attached document must use an allowed file type
- BR-RO-L211 Attachment file name: 200 characters at most
- BR-TMP-5 Give each supporting document one attachment at most
- CII-DT-106 Each embedded attachment needs a file name
- CII-SR-476 A supporting document can hold only one attached file
- DE-R-022 Attached documents need unique file names