UBL-SR-08
EN 16931-1 layer: en16931
Checked against Peppol BIS Billing 3.0 2026.5
What does UBL-SR-08 mean? Invoice period shall occur maximum once
Why did my invoice fail UBL-SR-08?
The Invoice period group (BG-14), which defines the invoicing period start (BT-73) and end (BT-74) dates the invoice covers, may occur at most once at document level. In UBL this is the header cac:InvoicePeriod, and only one such period is allowed for the whole invoice.
Official rule text
Invoice period shall occur maximum once
Common causes
- A header cac:InvoicePeriod is emitted more than once, e.g. one for start and one for end.
- Line-level periods are accidentally serialized at document level.
- Billing spans multiple periods and each is added as a separate header InvoicePeriod.
How do I fix it?
Use one header period: <cac:InvoicePeriod><cbc:StartDate>2026-06-01</cbc:StartDate><cbc:EndDate>2026-06-30</cbc:EndDate></cac:InvoicePeriod> and place any distinct per-line periods under cac:InvoiceLine/cac:InvoicePeriod instead.
Related rules
UBL-SR-01 · UBL-SR-02 · UBL-SR-03 · UBL-SR-04 · UBL-SR-05 · UBL-SR-06 · UBL-SR-07 · UBL-SR-09
Check your invoice against this rule
Paste it into the live demo, or call POST /v1/validate. See the quickstart.