Stripe vs. KSeF – how to invoice Stripe transactions to meet the KSeF obligation?

Mandatory KSeF from 2026 – what does it mean for businesses?

The National e-Invoice System (KSeF) is the Ministry of Finance's platform for issuing, sending, and storing structured invoices, i.e., e-invoices in XML format compliant with government requirements. From 2026, using KSeF becomes mandatory for most entrepreneurs – this means the end of paper invoices and traditional document exchange between companies. All sales invoices will have to be submitted to the central system almost immediately after being issued, and the tax office will also gain immediate access to them. As a result, entrepreneurs must adapt their invoicing processes so that every sale is electronically invoiced and registered in KSeF within the required timeframe.

Key KSeF dates:

- February 1, 2026 – KSeF obligation for large companies (revenue above 200 million PLN per year).
- April 1, 2026 – obligation for all other entrepreneurs (i.e., the majority of small and medium businesses).
- January 1, 2027 – by this date, micro-businesses (sales up to 10,000 PLN per month) will get additional time; from 2027, even the smallest entrepreneurs will be covered by KSeF.

Importantly, receiving structured invoices will be mandatory for all companies starting from February 2026 – even if the smallest businesses may not yet need to issue their own e-invoices, they must be ready to receive documents from suppliers through KSeF (e.g., fuel invoices). A transitional period has also been introduced: until the end of 2026, no penalties will be imposed for any errors in handling the new system. However, this does not change the fact that every invoice must ultimately be registered in KSeF very soon after the sale.

Why doesn't Stripe work with KSeF?

Stripe is a global payment platform that enables accepting online payments from around the world. Although Stripe has been officially operating in Poland since 2019 and supports local payment methods, it does not offer the ability to issue Polish invoices or integration with KSeF. Stripe focuses on payment processing – it leaves tax and invoicing matters to the seller. It does provide tools such as Stripe Tax (for calculating VAT) and sends customers transaction confirmations (so-called receipts), but this does not replace a Polish VAT invoice or accounting requirements in Poland. In practice, therefore, if you sell something through Stripe (e.g., an online course, e-book, or other digital product), you must take care of issuing an invoice compliant with Polish law yourself.

This problem has existed for a long time – Stripe does not "know" what a Polish VAT invoice looks like (with the buyer's tax ID, the correct VAT rate, proper numbering, etc.), so every sale must be invoiced independently. Many online creators and small businesses have been managing this manually: for example, issuing invoices in bulk once a month in an external accounting program or on customer request. Such manual invoicing for Stripe transactions can be burdensome and error-prone – it's easy to miss something, mix up data, or simply not keep up with larger sales volumes. Now, with the introduction of KSeF, an additional obligation arises: not only must you issue a VAT invoice, but also submit it to the government system. This means the need for even faster and more automated invoicing of every transaction.

Issuing invoices within 4 hours – the new reality of e-invoicing

With KSeF, the speed at which we must document sales will change. Previously, an entrepreneur had up to 15 days of the following month to issue an invoice, but in the era of e-invoices, this will be drastically shortened. Every invoice must be submitted to KSeF very quickly – practically within several dozen hours, and ultimately even in near-real-time. According to transitional provisions, invoices were planned to be required to be sent to KSeF within 24 hours of being issued, and there were also proposals to extend this deadline to 72 hours or 5 days. Regardless of the final regulations, an entrepreneur can no longer wait weeks to submit a document – a fast response after the sale is essential.

In practice, to sleep soundly, it's worth issuing and sending the e-invoice to KSeF almost immediately after the sale – ideally within a few hours. Imagine a sale at midnight – if you don't invoice it right away, the next day you could easily exceed the allowed deadline. Automation is key here. Manually creating an invoice for every transaction and uploading it to the government system within such a short time would be very difficult, especially when sales happen 24/7 (typical for online sales). That's why businesses need a solution that within those few hours of payment will automatically generate an invoice and send it to KSeF – without human intervention.

Polish invoicing programs with KSeF integration

The good news is that many popular accounting and invoicing programs in Poland have adapted to KSeF. Software providers know their users will need to handle e-invoices, so they already offer integrations with the government system. For example:

- Fakturownia.pl – introduced free KSeF integration, enabling automatic sending and retrieving of invoices from its system to KSeF. An issued invoice can be submitted with one click, and the user doesn't need to log into the government portal.
- wFirma – made e-invoice handling available; sales invoices issued in the system are automatically sent to KSeF right after being saved. This way, the entrepreneur doesn't worry about the technical side of submission at all – it happens in the background.
- inFakt – a simple invoicing system for micro-businesses has also integrated with KSeF. The user just needs to enter the KSeF authorization token in the app, and inFakt will automatically send invoices to KSeF, retrieve them, and receive the status and KSeF number for each invoice. The creators of inFakt boast that their users can already send e-invoices today directly from the program.
- iFirma – a popular accounting platform is also preparing full KSeF integration. The company announces it will support automatic invoice sending, receiving documents from KSeF, and other features (e.g., retrieving contractor data from GUS), so that iFirma users can meet the new obligations without complications. (When KSeF comes into effect, this integration should already be available or just before launch – it's worth following iFirma's announcements).

In addition to the above, larger ERP systems (like Comarch Optima) and other tools (e.g., Saldeo Smart) also offer their own KSeF modules. However, for the average online creator, the key are these smaller, affordable applications that they already know and use daily for invoicing. So if you use any of the above programs for accounting, you already have a foundation for meeting KSeF obligations – you just need to ensure that your Stripe sales reach that invoicing program.

Automation: Stripe -> invoicing -> KSeF with Striptu

The remaining question is: how to connect Stripe with these invoicing programs so that every transaction is immediately invoiced and sent to KSeF? This is where Striptu comes in – a Polish SaaS tool created specifically to bridge the gap between global sales platforms and local accounting requirements. Striptu enables integrating your Stripe account (as well as platforms like Kajabi or ThriveCart, which process payments through Stripe) with your chosen invoicing system, such as Fakturownia. In practice, it works as follows:

1. Connect Stripe with Striptu: a few clicks allow you to authorize Striptu's access to your Stripe account. From that moment, the tool will be able to "see" new transactions.
2. Connect Striptu with your invoicing program: you choose, e.g., Fakturownia.pl (currently available integration) or another system (integrations with ifirma, inFakt are planned – according to the product roadmap). You provide the API key for your invoicing program account so that Striptu can issue documents on your behalf.
3. Automatic invoice generation: as soon as a new payment appears in Stripe (e.g., someone buys your online course), Striptu automatically creates a VAT invoice in the connected accounting program. The invoice contains all necessary data – the customer, the amount in PLN, the VAT rate or reverse charge information (e.g., NP for foreign sales), numbering, etc. This eliminates manual data entry.
4. Sending the invoice to KSeF: because your invoicing program is integrated with KSeF, the freshly issued invoice immediately goes to the government system. This happens automatically – for example, in wFirma, the submission occurs automatically after saving the invoice. You don't need to take any additional steps. The invoice receives a unique identifying number from KSeF, confirming its official registration.
5. Archival and compliance: the e-invoice goes to your KSeF archive (where it will be stored for 10 years) and is saved in your accounting program. You can download it, print a PDF image with a QR code, but there is no longer a need to traditionally send it by email to the customer – the customer (buyer) can also receive it through KSeF. Everything is done in compliance with Polish regulations, and you meet the KSeF obligation effortlessly.

Thanks to such a solution, the entire process from payment to a legally compliant invoice is automated. Creators who previously wasted time manually invoicing every Stripe sale can now focus on their business rather than paperwork. Importantly, the problem of Stripe's lack of integration with local invoicing systems is not unique to Poland – globally, many companies had to find ways to connect Stripe with national e-invoicing solutions. Stripe itself even started offering partner e-invoicing apps on its Marketplace (e.g., for Italy or Belgium), because it acknowledges that its own tools do not generate or send e-invoices directly to tax authorities. In Poland, Striptu fills this gap together with integrations to popular accounting programs.

Stripe vs. KSeF – summary of the challenge and solution

Mandatory e-invoicing (KSeF) from 2026 forces online entrepreneurs to change their habits in documenting sales. If you use Stripe to accept payments, you must ensure fast issuance of VAT invoices and their submission to KSeF. Stripe itself won't help you with this – it won't issue a Polish invoice or connect with the Ministry of Finance's system. Fortunately, you can use Polish invoicing programs integrated with KSeF (like Fakturownia, wFirma, inFakt, iFirma) and automate data flow with Striptu. As a result, sales made through Stripe will be legally invoiced according to Polish regulations, and every invoice will be in KSeF within the required 4, 24, or 72 hours – without stress and without manual data entry. Stripe remains an excellent payment processing platform, and with the right integration, you'll meet the KSeF obligation and keep your accounting in order. Prepare your business now for the upcoming changes, so that in 2026 KSeF is no longer a problem, but a natural part of your automated online business.