Obligation to Receive Invoices in KSeF from 1 February 2026 for All Companies and How to Automate This Process in n8n

TL;DR: From 1 February 2026 all companies in Poland will have to receive invoices exclusively via KSeF (Poland mandatory national e-invoicing system). Manual login and downloading documents will take hours weekly, which with a larger number of contractors becomes a problem. Below I show how to handle it in n8n – a tool that allows building such automations without writing code from scratch.

KSeF obligation from February 2026 – what exactly is changing

From 1 February 2026 the obligation applies already not only to selected groups of taxpayers. Every company, regardless of turnover, will have to receive invoices via KSeF. This means the end of receiving invoices by email or on paper in business relations.

In practice companies will have to either log in daily to the Ministry of Finance portal, or integrate their systems with the KSeF API. The second solution is the only sensible one with more than a few invoices per month.

There is no room for half-measures here. If you do not prepare the integration, someone in the company will have to do it manually. How to determine the KSeF obligation deadline for your company is a good starting point if you still do not know from when exactly this applies to you.

Why manual receipt of invoices in KSeF is a bad idea

Logging into the portal, searching for new invoices, downloading PDFs and entering them into the accounting system takes time. With 20 invoices weekly this is easily 3–4 hours that someone has to devote.

Errors happen – an invoice may be overlooked, incorrectly booked or downloaded in the wrong version. KSeF returns documents in structured form, but without automation you lose this benefit.

KSeF step by step for SMEs shows how many companies still approach this manually and what consequences it has. I do not recommend this path in the long term.

What is n8n and why it is suitable for KSeF

n8n is a process automation tool that allows connecting different APIs and services using nodes. According to information from the n8n.io website it combines automation capabilities with AI elements, giving flexibility in building workflows.

It is not a magical solution. It requires configuration, testing and understanding how the KSeF API works. But once built, the workflow can download invoices, save them to a folder, send notifications and integrate with the accounting system.

I used general knowledge about n8n with similar integrations. The tool allows the use of HTTP Request nodes for communication with KSeF, as well as processing the JSON that the system returns.

How to build invoice receipt automation in n8n – specific steps

Start with a self-hosted n8n instance. Cloud hosting has execution limits, and with daily KSeF checking it is better to have full control over the data.

In the workflow you add a time trigger (e.g. every hour during working hours). Then an HTTP Request node that authorizes to the KSeF API and downloads the list of new invoices since the last check.

For each invoice you download the full document, parse it and save it in the appropriate place. You can add a step with AI agents that based on the invoice content suggests the accounting category – this speeds up the work, but does not replace the accountant.

Test this on the KSeF test environment. The API has query limits, so do not make a loop that queries every minute. Realistically checking every 30–60 minutes is sufficient.

In dokodu.it it is described how n8n automates processes from order to inventory update. Similar logic is used with invoices.

Self-hosted n8n on VPS – practical notes for KSeF integration

With automations related to invoices it is worth considering self-hosted n8n on your own server. Invoice data is tax information – better to keep it with yourself.

Self-hosted n8n on own VPS: Docker, Traefik and backups shows the technical aspects of such installation. I use a similar setup because it gives stability and no execution limits.

Hosting on VPS, for example offered by home.pl, allows matching resources to needs. It is not the cheapest option, but with continuous workflows it makes sense.

Most common problems with KSeF automation in n8n and how to avoid them

The first problem is authorization. KSeF tokens expire, so the workflow must refresh them. Without this the automation fails after a few hours.

The second is error handling. KSeF sometimes returns 429 errors (too many queries) or certificate problems. You must add branching in n8n that retries the query or sends an alert.

The third is parsing invoices. The XML/JSON structure is complicated. Here you can use AI agents to extract key fields, but always verify the result manually at the beginning.

KSeF in practice: the most common integration errors and how to avoid them covers many of these issues. It is worth reading before building your own workflow.

In summary, automation of invoice receipt in n8n is possible and sensible, but requires time to build and test. It is not something you turn on in one evening and forget. If you do not have experience with APIs, it is better to start with simpler workflows.

(n8n allows such integrations, but success depends on how well you prepare the logic and tests.)

FAQ

When exactly does the obligation to receive invoices via KSeF for all companies begin? From 1 February 2026. There are no longer exceptions for small companies or turnover limits.

Does n8n require programming skills for KSeF automation? It does not require writing code in the classical sense. You use nodes and a graphical interface, but knowledge of API and conditional logic is needed.

Is self-hosted n8n necessary for KSeF? It is not necessary, but recommended due to the amount of data and lack of limits. The cloud version also works, but at larger scale it is better to have control.

Can AI agents completely replace an accountant with KSeF invoices? No. AI agents can help with categorization and data extraction, but the ultimate responsibility for booking lies on the human side.

How much time does building such automation take? With basic knowledge of n8n – from 8 to 20 hours spread over several days, including tests. This is an estimate based on the general complexity of API integration.