From February 1, 2026 every company selling in Poland must issue invoices through the National e-Invoicing System (KSeF). A store that skips it is breaking the law. If you run Magento 2 + Comarch Optima — we have a plan, and 80% of the road already paved.
KSeF is a central e-invoice archive run by the Polish Ministry of Finance. From Feb 1, 2026 every B2B invoice must be submitted to KSeF API within 24h. Without submission — the invoice is invalid, the cost isn't deductible, and sanctions apply.
Most Magento + Optima shops are in one of three states today: (a) they issue invoices manually in Optima with no KSeF, (b) they have Optima Cloud with KSeF enabled but Magento doesn't know about it, (c) they patch it with custom development costing PLN 10,000-30,000.
Option (c) is the usual choice for 80% of stores. Agency pricing for "KSeF integration for Magento" in 2026 starts at PLN 8,000 and often requires rewriting half of the invoicing module. Plus maintenance. Plus every ministry-side schema change becomes a separate invoice.
SISL Optima Connector v0.3.6 doesn't yet send invoices to KSeF directly — Optima does. But the product already solves 80% of the integration problem.
Operator issues FA in Optima with description MG-100000123, Magento auto-creates the matching Invoice. Partial documents supported (1 of 5 units → 1 in Magento).
Tax ID, company data, address — synced from Optima KntKarty to Magento customer_entity. KSeF requires an up-to-date NIP register.
B2B (b2b.shop) and B2C (retail.shop) can have different issuing entities — Optima holds the list of legal entities, we map them to website.
Everything runs on your infrastructure, fiscal data doesn't pass through our cloud. Your auditor / accountant / ministry inspector gets the full module + .NET microservice code under NDA.
Direct API call Magento → KSeF on every Invoice creation. MF token auth, retry on timeouts, UPO (official acknowledgement) stored in order history.
For shops already running Optima Cloud with KSeF enabled — Magento receives the UPO from Optima and posts it on the Magento Invoice. No duplicate submissions.
We don't charge extra for KSeF. It's a major-version upgrade, and all major-version upgrades are included in the PLN 300/mo subscription. v0.3.6 subscribers will auto-receive v0.7.0 on release.
Implementation starts June 2026 (right after v0.4.0 order forward). Plan: 1.5–2 months of dev + 4 weeks of testing on the MF sandbox + 2 weeks soft rollout. Target release: September 2026 — 5 months before the deadline, with buffer.
What you do now (nothing required yet): register your NIP and obtain an MF token in the Ministry of Finance panel (10 minutes, free). When v0.7.0 ships — paste the token in Magento admin and KSeF Gateway works.
What we do: track the MF API changes (3 schema versions of FA(2) already), monitor the MF sandbox, test edge cases (split invoice, correction, cancellation). Customer doesn't have to follow this.
Yes. Active subscribers on the v0.7.0 release date receive the update automatically through the "Updates" panel in Magento admin. Click Apply update, KSeF Gateway is available.
v0.7.0 has an "Optima sends, we read UPO" mode. Your Optima Cloud continues to submit invoices to KSeF, we only receive the acknowledgement and post it on the Magento Invoice. No double-submission.
Hotfixes are included in the subscription. Critical changes (e.g. new FA(3) schema) ship as v0.7.1 within 24–48h. We never drop support.
Yes. Under NDA you get the full PHP module + .NET microservice source. Your auditor / accountant / MF inspector can review to confirm fiscal data flows correctly.
Yes. podatki.gov.pl/ksef. All B2B invoices issued by PL-registered entities must go through KSeF from Feb 1, 2026. E-commerce shops issuing VAT invoices — fully covered. The deadline was already postponed once (from 2024) — plan for Feb 2026.
v0.3.6 will keep working for product / stock / customer sync — that doesn't disappear. But you'd handle KSeF elsewhere (Optima Cloud, custom dev, another vendor). At that point SISL Optima Connector stops being a "complete solution" for your setup.
The earlier we start the conversation, the more buffer you have for testing + integration. Email [email protected] with subject "KSeF" — we reply the same business day with a concrete plan for your setup (Magento + Optima Cloud / on-prem Optima / existing custom KSeF dev).