What it means
When the seller and the buyer are both in Germany, every document attached to the invoice (BG-24) must have a unique file name in the attached document (BT-125). The official text says capitals do not count, so Timesheet.pdf and timesheet.PDF are the same name. The test compares the names of attachments embedded in the invoice file. Links to documents elsewhere have no file name here.
Why it matters
The recipient's software unpacks the attachments by name. Two with the same name can overwrite each other, so one document is lost or the wrong one is shown. The invoice is rejected.
How to fix it
Open the attachments on the invoice in your invoicing software and rename the duplicates, for example timesheet-march.pdf and timesheet-april.pdf. If the same document was attached twice by mistake, remove one copy. When you compare names, ignore capitals.
The rule as published
Read the rule on the publisher's site
Business terms: BG-24, BT-125
Where this rule applies
| Rule set | Version |
|---|---|
| Peppol BIS Billing 3.0 (invoice) | 2026.5 |
| Peppol BIS Billing 3.0 (credit note) | 2026.5 |
Check your file
Drop your e-invoice to see whether DE-R-022 still fails, and which other rules do.
Related rules
- BR-TMP-5 Give each supporting document one attachment at most
- BR-52 Document reference is required
- BR-DEX-01 Attached document must use an allowed file type
- BR-RO-A051 An invoice can have at most 50 supporting documents
- BR-RO-L211 Attachment file name: 200 characters at most
- BR-TMP-4 Give each supporting document one description at most