Stripe Integration with InFakt: A Comprehensive Guide for 2026

Why connect Stripe and InFakt?

Stripe is a global payment system that enables accepting transfers from around the world. Its advantage is ease of implementation and a wide network of integrations, but the platform does not issue Polish VAT invoices or support sending invoices to the National e-Invoice System (KSeF).
InFakt is a Polish accounting and invoicing application aimed primarily at micro-entrepreneurs and sole proprietorships. For years, it has been developing its own API, enabling companies to connect online shops, CRM systems and sales platforms. According to official InFakt data, more than 1,200 companies already use the API, approximately 390,000 invoices are issued monthly, and the number of API requests reaches 26 million. This makes InFakt one of the most frequently integrated accounting programmes in Poland.

The upcoming KSeF regulations mean that entrepreneurs must not only issue a VAT invoice but also send it in the appropriate format to the government system. Manually transmitting each invoice is impractical — which is why it is worth automating the entire process by connecting Stripe with InFakt using a dedicated integrator. In this article, we explain what KSeF is, why Stripe → InFakt integration is the simplest path to legally compliant invoicing, and how to configure such a connection step by step.

What is KSeF?

The National e-Invoice System (KSeF) is a government IT system for issuing, transmitting, receiving and storing structured invoices. The platform automatically assigns a unique number to each invoice and provides access to documents for at least 10 years. From 1 February 2026, the system will gradually cover all entrepreneurs in Poland.
Implementation deadlines are as follows:

- 1 February 2026 — KSeF becomes mandatory for companies that exceeded 200 million PLN in sales (including tax) in 2024.
- 1 April 2026 — mandatory for all other entrepreneurs.
- Until the end of 2026, the smallest businesses (sales up to 10,000 PLN per month) may continue issuing traditional invoices but must be ready to receive invoices via KSeF.

The implementation of KSeF aims to digitise the invoicing process, reduce errors and facilitate tax audits. However, the system requires that invoices be submitted almost immediately after issuance — which in practice demands automation. Using accounting software integrated with KSeF is one of the recommended approaches.

Why do you need a Stripe → InFakt integration?

Stripe does not offer Polish invoices or KSeF

Stripe makes it easy to accept payments but does not generate Polish VAT invoices — transaction confirmations (receipts) do not contain the buyer's NIP number, the correct VAT rate or numbering compliant with Polish regulations. They are certainly not structured e-invoices compatible with KSeF. This means each Stripe transaction must be invoiced in your own system and sent to KSeF. Manually re-entering data from hundreds of payments is laborious and error-prone. With KSeF in place, instant invoice submission becomes mandatory, so traditional monthly reconciliation will no longer work.

InFakt with KSeF support and a rich API

InFakt provides a REST/JSON API that allows automatic invoice issuance, payment monitoring, client database management and data import/export. KSeF connectivity can be configured directly through the API: InFakt supports bulk invoice submission to the government system, cost document import and status checking. The system also supports webhooks, giving you real-time notifications about events (e.g. invoice payment). From a micro-business perspective, this is a simple solution: once connected, you get automatic KSeF support without programming.

Striptu — the bridge between Stripe and InFakt

Striptu.com is an integration platform that mediates between Stripe and Polish accounting software such as InFakt, Fakturownia, wFirma and iFirma. Our tool captures information about new payments from Stripe (via webhook/API) and creates sales invoices in the chosen accounting programme. This means you do not need to manually re-enter data or build your own API script. InFakt, with built-in KSeF support, sends the e-invoice to the government system and retrieves the KSeF number and receipt confirmation. The integration can work fully automatically (invoice sent immediately) or semi-automatically, when you want to approve it first.

How to configure the Stripe → InFakt integration via Striptu (step by step)

Below are step-by-step instructions. We assume you have already created a service in Striptu and authorised your Stripe account (entered the API key). Now it is time to connect InFakt.

1. Open InFakt integration settings

After enabling the InFakt integration in the Striptu wizard, you will be redirected to the Settings view.
In the Striptu dashboard, select the created service and go to the Settings → InFakt tab to configure the connection.

2. Enter the API token and test the connection

1. In the InFakt section, enter the API Token — a unique authorisation key.
2. Click Test connection so we can verify access.

You can find the API Token in the InFakt dashboard: after logging in, click your name in the upper right corner, select Other options → API and generate a new key. Make sure to grant it permissions for creating and reading invoices, as we need these rights for proper operation.

3. Configure the income tax rate (flat-rate)

If you settle accounts on a flat-rate basis, InFakt requires specifying a default income tax rate. You can set it in the Striptu dashboard — it will be transmitted to InFakt along with the invoice. More about flat-rate configuration can be found in the documentation.

4. Additional settings

Automatic invoice email sending — after issuing a document, we can ask InFakt to send the PDF to the email address from the Stripe transaction. You must have email sending enabled in the InFakt dashboard.
Default VAT rate — if you do not use the Stripe Tax module, Stripe does not pass the net amount. In this case, set a default VAT rate in Striptu (e.g. 23%) so the document contains the correct values.
Manual vs. automatic mode — in InFakt you can decide whether invoices should be sent to KSeF immediately after issuance or whether you want to approve them first. Semi-automatic mode is useful if you need additional control.

5. Test transaction

Before launching the automation, make a test transaction in Stripe test mode (e.g. use a fictitious card). Check whether the invoice appeared in InFakt, whether it has the correct number and all required fields, and whether it was properly sent to KSeF. In case of errors, adjust the settings and make another attempt.

Why you should not build your own integration

Theoretically, you could independently connect the Stripe API and KSeF API. Stripe provides an interface for retrieving payment data, and the Ministry of Finance provides the KSeF API for submitting e-invoices. In practice, however, such integration is complex and expensive to maintain. It requires generating invoices in XML FA_VAT format compliant with KSeF, constantly updating schemas, proper authentication (Trusted Profile, certificate) and ensuring key security. More about the challenges of building your own integration can be found in our article.
For most entrepreneurs — especially micro-businesses and online creators — building your own solution is not cost-effective. Using a ready-made integration platform like Striptu is simpler and lets you focus on business rather than programming.

Benefits of Stripe → InFakt → KSeF automation

- Time savings — invoices are issued and sent to KSeF automatically after every Stripe transaction; no need to manually re-enter data or generate files.
- Regulatory compliance — InFakt has built-in KSeF support and enables submission of structured invoices, which guarantees full compliance with Polish law.
- Fewer errors — thanks to InFakt's API and our integration, transaction data (amount, client details) is transferred automatically, minimising the risk of missing invoices or incorrect documents.
- Constant oversight of invoice statuses — InFakt can monitor document statuses in KSeF; if there are problems, you immediately know which invoices require attention.
- Fast PDF delivery to the customer — after issuing an invoice, InFakt can automatically send the PDF file via email, so the buyer immediately receives proof of purchase.

Summary

KSeF is introducing a revolution in Polish invoicing: from 1 February 2026, large companies, and from 1 April 2026, other businesses will have to issue invoices in structured form and immediately submit them to the government system. Stripe — although it handles payments excellently — does not issue Polish VAT invoices and does not integrate with KSeF. That is precisely why integration with InFakt via Striptu is so important.

InFakt offers simple KSeF support and a rich API, while Striptu acts as a "bridge" between the global payment gateway and the local accounting system. As a result, every Stripe payment generates a VAT invoice that goes to InFakt, and from there to KSeF. Everything runs automatically — from the moment of payment, through document issuance, to its submission to the government system and sending the PDF to the customer.
If you sell online (courses, e-books, SaaS) and use Stripe, do not wait until the last moment — test the Stripe → InFakt → KSeF integration now. This way you will avoid a stressful rollout in 2026, gain peace of mind and more time to grow your business.