KSeF for Allegro Sellers: How to Handle Structured Invoices and Visualization PDFs

Overview

Poland's KSeF (Krajowy System e-Faktur) is a centralized system for structured electronic invoices. Allegro sellers who must comply with Polish invoicing rules will typically need to issue invoices in KSeF's structured format and often provide a readable PDF visualization for customers, carriers, or accounting records. This guide explains the practical steps, integration options, compliance considerations, and common pitfalls for Allegro sellers, written for beginners.

Why KSeF matters for Allegro sellers

Using KSeF ensures legally accepted, machine-readable invoices that speed up tax reporting and reduce processing errors. For Allegro sellers, correctly linking marketplace orders to KSeF invoices improves reconciliation, reduces disputes, and ensures VAT compliance. Sellers must reconcile Allegro order data (order number, buyer details, item lines, fees) with their invoice fields before submitting to KSeF.

Key concepts explained

• Structured invoice: An invoice represented in a standardized XML-like data format required by KSeF. It contains discrete fields (seller, buyer, line items, VAT rates, totals) rather than a single PDF image.
• Visualization PDF: A human-readable PDF generated from the structured invoice to present to customers, attach to shipments, or archive. It is not the legal structure itself but a representation generated from the structured data.
• Invoice flow: Create invoice in your ERP/accounting tool -> transform/mapping to KSeF structure -> submit to KSeF (API or certified provider) -> receive KSeF identifier and optionally retrieve visualization PDF -> archive for accounting.

How to implement KSeF for Allegro orders — step by step

1. Collect and map Allegro order data: Pull order number, buyer name, NIP (VAT ID), address, delivery method, item SKUs, quantities, prices, discounts, and Allegro fees. Always include the Allegro order ID in the invoice reference field so you can reconcile payments and returns.
2. Choose an integration path: Options include using your accounting/WMS software with built-in KSeF support, a certified KSeF intermediary, or direct API integration with KSeF. For many small sellers, a billing provider that connects Allegro and KSeF is the simplest route.
3. Map invoice fields to KSeF structure: Ensure each line item, VAT rate, and monetary amount maps to the correct KSeF field. Pay close attention to currency, rounding rules, and how fees (Allegro commissions, shipping) are represented — as separate lines or adjustments.
4. Validation and test environment: Use KSeF’s sandbox (test) environment where available to validate invoices before sending real documents. Most providers offer validation tools that catch missing required fields or incorrect formats.
5. Submit and obtain KSeF response: Send the structured invoice to KSeF via API or provider. On acceptance, KSeF returns an identifier and status. Capture and store this identifier in your order system and attach it to the Allegro order record.
6. Retrieve or generate the visualization PDF: Many providers and KSeF APIs allow you to request a PDF visualization generated from the structured XML. Store the PDF alongside the KSeF XML and your internal invoice copy for customer service, shipping, and audits.
7. Archive and backup: Keep both the structured XML and PDF visualizations for statutory retention periods. Ensure the audit trail links the Allegro order, payment records, and any corrections or credit notes.

Best practices for Allegro sellers

• Always include Allegro order identifier: This speeds reconciliation and customer service.
• Standardize product SKUs and tax classification: Consistent product data reduces mapping errors when generating structured invoices.
• Use a middleware or certified provider if you lack internal dev resources: These providers handle format compliance, signing, and API nuances.
• Validate before sending: Run invoices through the KSeF test environment or provider validators to catch errors and avoid rejections.
• Store both structured file and visualization: The XML is the authoritative legal record; keep the PDF for business operations.
• Automate linking to Allegro transactions: Automatically attach invoice numbers and KSeF IDs to Allegro order notes where possible to avoid manual lookups.

• Missing or incorrect buyer NIP (VAT ID): Always verify NIP numbers before issuing invoices — mismatched NIPs cause rejections or audit issues.
• Improper mapping of fees: Treat Allegro commissions and shipping correctly — decide whether to show them as separate invoice items or net adjustments and map consistently.
• Relying on PDF only: PDF visualizations are for readability; the structured XML is the compliance artifact. Do not assume a PDF submission alone satisfies KSeF requirements.
• No audit trail linking: Failing to store KSeF IDs with Allegro orders makes returns, disputes, and audits time-consuming.
• Skipping tests: Sending invoices without validating in sandbox/test can lead to rejections and delays.

Handling corrections, cancellations, and credit notes

Use the structured correction or credit note document types when modifying an already-submitted invoice. KSeF workflows typically require you to reference the original structured invoice identifier. Ensure your system captures the relationship between original invoices and corrections, and reflect those links in Allegro order records to maintain consistent customer communications.

Example integration scenarios

• Small seller, low volume: Use an invoicing app that integrates with Allegro and offers KSeF support. The app handles mapping, submission, and PDF generation with minimal setup.
• Medium seller, moderate automation: Use an accounting system that pulls Allegro orders via API, maps to your product catalog, and submits structured invoices through a certified KSeF provider. Store returned KSeF IDs in your ERP.
• High-volume seller or enterprise: Build a direct integration: ERP/OMS exports structured XML, a middleware layer validates and enriches data (adds Allegro IDs, fees), and a KSeF gateway handles secure submission and retrieval of PDF visualizations and identifiers.

Compliance and recordkeeping

Keep the XML, the visualization PDF, the KSeF acceptance response, and proof of submission in your records for the legally required retention period. Ensure access controls and backups are in place in case of audits. Work with your accountant or tax advisor to confirm retention timelines and any industry-specific requirements.

Final checklist for Allegro sellers

• Map Allegro order fields into invoice structure (order ID, buyer NIP, item lines).
• Validate invoice in KSeF test environment.
• Submit structured invoice and capture KSeF identifier.
• Retrieve/store the visualization PDF for customer-facing needs.
• Archive XML, PDF, submission response, and link to Allegro transaction.
• Use consistent SKU and tax rules to avoid mismatches.

Conclusion



For Allegro sellers, adopting KSeF structured invoicing and managing visualization PDFs is a mix of compliance and operational integration. By mapping Allegro order data accurately, choosing the right integration approach, validating submissions, and storing both structured and readable copies, sellers can streamline tax compliance, improve reconciliation, and reduce disputes. If development resources are limited, partner with a certified provider or accounting tool that supports Allegro-to-KSeF workflows to simplify implementation.