KSeF for WooCommerce: Implementation Guide

This is a technical guide, not a client delivery or tax advice. It explains what Polish WooCommerce stores need to consider for KSeF, based on the rules and product behavior documented in July 2026.

KSeF timelines for receiving and issuing invoices

The B2B and B2C split at checkout

Authentication, FA schema mapping, corrections and offline handling

When an existing invoicing system is enough, and when a custom integration is needed

The guide maps 3 implementation paths: an existing invoicing system, invoice generation within WooCommerce, or a custom flow for edge cases such as corrections, deposits, multiple tax IDs or international sales.