Translation. Original: offline/automatyczne-okreslanie-trybu-offline.md

Automatic offline mode determination

04.10.2025

In the case of invoices sent as online (offlineMode: false), the KSeF system may assign them offline mode - based on comparison of the issue date with the processing acceptance date.

Mechanism algorithm

For invoices sent as offlineMode: false, the system compares:

• issue date of the invoice (issueDate, e.g., P_1 for invoice compliant with FA(3)),
• acceptance date of the invoice in the KSeF system for further processing (invoicingDate).

Rules:

• If the calendar day from issueDate is earlier than the calendar day from invoicingDate (comparison by date, not by time), the system automatically marks the invoice as offline, even if it was not declared as such.
• If the day of issueDate and the day of invoicingDate are the same, the invoice remains online.

The invoicingDate value depends on the transmission mode:

• batch session - invoicingDate is the session opening time (equal to dateCreated returned in session status - GET /sessions/{referenceNumber}),
• interactive session - invoicingDate is the invoice transmission time.

This means that if, for example, an invoice was issued on 2025-10-03 (P_1) and sent on 2025-10-04 at 00:00:01, despite offlineMode: false, it will be marked as an offline invoice.

Examples

Batch session opened at 23:59:59 on October 3rd: Even if the package is sent after midnight, invoices will remain online – because invoicingDate is October 3rd (session opening date).

Interactive session started at 23:59:59 on October 3rd, and invoices were sent after midnight: If P_1 = 2025-10-03, the system will mark them as offline – because the day of P_1 is earlier than the transmission day.

Related documents

• Offline modes