What it means
When the seller and the buyer are both in Germany and the invoice has a seller contact (BG-6), that contact must include a telephone number (BT-42). A blank or spaces-only value counts as missing. The rule only checks that something is filled in, not the format of the number.
Why it matters
The buyer needs a way to reach you about the invoice. An empty phone number fails the check and the invoice is rejected.
How to fix it
In your invoicing software, open your sender or company details and find the phone number in the contact section. Enter a number where the buyer can reach you or your accounts team. Some software keeps this apart from the phone number on your letterhead, so check the contact person section as well.
The rule as published
Read the rule on the publisher's site
Business terms: BT-42
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-006 still fails, and which other rules do.
Related rules
- BR-DE-6 Seller contact phone is required
- BR-DE-27 The seller's phone number should contain at least three digits
- BR-RO-L1005 Seller contact phone number must be 100 characters or fewer
- DE-R-027 Seller contact phone number should have at least three digits
- DE-R-007 A seller email address is required between German parties
- DE-R-008 The buyer city is required between German parties