KSeF and Purchase Invoices: A Practical Guide for Companies

For experienced managers and operational teams, the key challenge posed by the introduction of KSeF is maintaining business context: how to quickly identify a specific purchase among XML data and link it with a physical site acceptance protocol, a CMR transport document, or a business travel request? Without proper preparation, a process designed to automate work can easily become a bottleneck. Here’s how to efficiently handle purchase (cost) invoices in KSeF.

Table of contents

1. How to Download Purchase Invoices from KSeF?
2. Purchase Invoices in Business Processes
3. Security and Verification: Stopping “Scam” Invoices
4. Summary

How to Download Purchase Invoices from KSeF?

There are two ways to navigate the new reality:

1. Using free government tools — a process that resembles working manually with an archive. Each time, you must log in to the portal, review the list of documents, and download them yourself. The biggest risk: a complete lack of notifications. KSeF will not inform you about new invoices. This means your team must keep track of payment deadlines and ensure all expected invoices have arrived.
   See the guide: How to download invoices from KSeF.
2. Integrating KSeF with your existing ERP or Document Workflow (EOD) systems. With integration, you gain invoice notifications, a human‑readable document view, and automatic invoice routing to the correct person or project. This reduces errors, prevents payment delays, and — over time — lowers operational costs. A tool that connects KSeF with business systems is KSeF Connector by GoNextStage.

Purchase Invoices in Business Processes

The biggest concern among accountants and operations directors is separating invoices from the supporting documentation, such as:

• in construction: acceptance protocols, stage‑completion reports;
• in transport: transport documents confirming delivery;
• in manufacturing: quality certificates or attestations;
• in travel‑heavy organizations: delegation request documents.

A structured invoice in KSeF is a pure data file — you cannot “attach” a scan of a protocol or certificate. To avoid chaos and manual matching of documents, you should use linking keys within the additional e‑invoice fields:

• Podmiot3 — ideal for adding data on intermediaries or final recipients. If you operate a large organization and goods go to a specific branch or subcontractor, entering these details allows your IT systems to automatically route the invoice to the correct unit.
• Opis faktury — used for all additional information needed for smooth processing: construction site ID, acceptance protocol number, travel request code, and other essential details.

With properly structured data, BPM‑class systems can match a KSeF invoice with documents sent by email or registered in the warehouse in milliseconds — this is where real automation gains emerge.

Security and Verification: Stopping “Scam” Invoices

Another concern for Finance Departments is the vision of invoices being automatically posted without validation. Will every invoice appearing in KSeF be seamlessly approved and paid? With fraud attempts on the rise, proper verification is more critical than ever.

Integrating KSeF with the GoNextStage KSeF Connector ensures a safe buffer. An invoice pulled from KSeF first lands in a “waiting room” within the document workflow system. There, it undergoes the standard approval path: purchase‑order matching, project manager verification, and final payment authorization. If a suspicious or incorrect document appears (e.g., a scam attempt), the company can report it through KSeF before any funds leave the account.

Summary

KSeF is a challenge, but also a powerful tool for tightening and accelerating company processes. Success lies not just in “connecting” to the government system, but in strategically using optional fields and integrating workflows. GoNextStage business analysts can support you during business analysis to ensure the setup is effective. Only then does the purchase invoice stop being a bookkeeping issue and become a smooth component of modern business management.