BT-73: Invoicing Period Start Date
Start date of the invoicing period covering the invoice.
Technical Specification
Conditional (0..1), typical for recurring service contracts
Semantic data format according to European Standard EN 16931-1
What does BT-73 mean?
BT-73 records the beginning of the service period for subscriptions, retainers, and maintenance contracts. Combined with BT-74 (end date).
XML Syntax & Code Example
<cac:InvoicePeriod>
<cbc:StartDate>2026-08-01</cbc:StartDate>
<cbc:EndDate>2026-08-31</cbc:EndDate>
</cac:InvoicePeriod>Business Rules & Schematron Checks
If both Invoicing period start date (BT-73) and end date (BT-74) exist, BT-74 shall not precede BT-73.
Check BT-73 in your invoice
Use the XML paths above to locate BT-73. A snippet illustrates this field; it is not a complete invoice. After correcting a value in the source application, export and check the entire file again.
Official specifications and rule sets
Requirements depend on the invoice profile and version. Consult the matching specification for mandatory fields, code lists and rules; Peppol-specific requirements do not automatically apply to every ZUGFeRD invoice.
Related Business Terms (BTs)
Create compliant E-Invoices easily
Create XRechnung and ZUGFeRD invoices in Billance and check the exported file locally. Use this guide to understand BT-73 and review your invoice details before sending.