The seller contact telephone number does not contain enough digits
`Seller contact telephone number` (BT-42) should contain at least three digits.
Only the issuer holds this value: Factlint reports it and never fabricates it. Test your invoice to find out whether it is affected.
The message your validator prints
Copied verbatim from the sealed artefact: this is the exact sentence the check prints when this rule fails.
[BR-DE-27] In BT-42 sollen mindestens drei Ziffern enthalten sein.
Quoted from schematron-xrechnung 3.0.2, licensed under Apache-2.0.
Common searches around this code
These phrases mirror what an integrator searches for: code, syntax, rule, business field and correction.
Test your file with this error in mind
Upload the invoice involved: the report will say whether this code appears, where it appears in the document, and whether Factlint can only report it or also fix it.
To automate this check in an ERP flow, call the validation API and link every returned code to its public page.
Why this error happens
The check is deliberately crude — it imposes no international format and no dialling code. So it catches only one thing, but the most common one: the field filled with a label (“See website”, “n/a”) to satisfy BR-DE-6.
How to fix it
Fill in a real number. A field filled to get past a check leaves the recipient with nobody to call, which is exactly what the rule exists to prevent.
XML correction example
<ram:CompleteNumber>030 / 123</ram:CompleteNumber>
<ram:CompleteNumber>+49 30 1234567</ram:CompleteNumber>