Download KSeF (Poland’s e-invoicing system) invoices to an Excel spreadsheet

Description

TL;DR;

Download invoices from Poland's KSeF (Krajowy System e-Faktur) and export them as an XLSX spreadsheet. Handles the full v2 authentication flow automatically.

Download KSeF invoices through n8n

What it does

This workflow connects to Poland's KSeF (Krajowy System e-Faktur) API v2, downloads invoice metadata for a configurable date range, and exports everything as a clean Excel spreadsheet (.xlsx).

The spreadsheet includes: KSeF number, invoice number, issue date, seller/buyer NIP and name, net/VAT/gross amounts, currency, invoice type, and more.

Who is it for

Polish companies and accountants who need to bulk-download invoice data from KSeF for bookkeeping, reconciliation, or tax reporting.

How to set up

Get your KSeF authorization token — log in at ksef.mf.gov.pl, go to token management, and generate a token. It looks like: YYYYMMDD-XX-XXXXXXXXXX-XXXXXXXXXX-XX|nip-XXXXXXXXXX|hash
Open the ⚙️ Config node and fill in:
nip — your 10-digit NIP
authToken — the KSeF token from step 1
startDate / endDate — the date range in ISO 8601 format (e.g. 2026-01-01T00:00:00Z)
subjectType — use Subject2 for invoices you received (as buyer), Subject1 for invoices you issued (as seller)
Click "Test workflow" — the spreadsheet will appear as binary output in the Write XLSX node

How it works (under the hood)

KSeF API v2 requires a 6-step authentication flow:

Fetch the RSA public key certificate from KSeF
Request a challenge (nonce + timestamp)
RSA-OAEP encrypt your token with the challenge timestamp
Initialize authentication — returns a temporary JWT
Poll the auth status until it's ready
Redeem the temporary JWT for a real access token

Only after step 6 can you query invoices. This workflow handles all of that automatically — you just provide your token and NIP.

Extending the workflow

Some ideas for what you can add after the Write XLSX node:

Write Binary File** — save the spreadsheet to disk
Send Email** (Gmail / SMTP) — email the spreadsheet as an attachment
Google Drive** — upload the spreadsheet to Drive
Postgres / MySQL** — write invoice data to a database for querying
Download Invoice XML** — add an HTTP Request node to GET /invoices/{ksefNumber} with the access token to download the full invoice XML

Requirements

A KSeF authorization token (generated at ksef.mf.gov.pl)
No external credentials or API keys needed in n8n — everything goes through the Config node
Works with n8n self-hosted and cloud

API reference

KSeF API v2: https://api.ksef.mf.gov.pl/v2
KSeF test environment: https://api-test.ksef.mf.gov.pl/v2
Official docs: https://www.gov.pl/web/kas/krajowy-system-e-faktur


Made with ❤️ by Greg Brzezinka Need help? Reach out to me!
Tags

ksef, poland, invoices, tax, e-invoicing, spreadsheet, xlsx, accounting

Categories

Finance & Accounting, Data Transformation