What it means
The date fields of a UBL invoice or credit note must be four digits for the year, two for the month and two for the day, separated by hyphens. This covers dates such as the invoice date (BT-2), the due date (BT-9), the start and end of a period, the delivery date (BT-72) and the VAT point date (BT-7). The check looks at the layout only, not at whether the date exists. Spaces around the date are ignored, but a time, a time zone or other separators fail.
Why it matters
This is a warning, so the file is still accepted. Receiving software expects one fixed layout, and a date in another layout may be misread or ignored. It is worth fixing before you send the invoice.
How to fix it
Find where the date comes from. Most invoicing software writes the correct layout by itself, so a bad date usually comes from a custom export, a date typed into a free-text field or a time stamp added to a date field. Make the value year, month, day with hyphens, for example 2026-11-05 for 5 November 2026, and remove any time or time zone.
The rule as published
Datumsangaben in UBL müssen im Format JJJJ-MM-TT (YYYY-MM-DD) übermittelt werden. Where this rule applies
| Rule set | Version |
|---|---|
| XRechnung 3.0 (UBL) | 3.0.2 |
| XRechnung 3.0 (UBL credit note) | 3.0.2 |
Check your file
Drop your e-invoice to see whether BR-TMP-6 still fails, and which other rules do.
Related rules
- BR-TMP-7 Dates in CII must use format 102 (YYYYMMDD)
- BR-TMP-5 Give each supporting document one attachment at most
- BR-TMP-4 Give each supporting document one description at most
- BR-TMP-3 Gross and net unit price must share the same base quantity
- BR-TMP-2 External document link must be a full web address