We go into the topic of “KSeF and Foreign Invoices” and quickly see that one question has several layers. Once the problem is whether it is necessary to issue a document in the KSeF at all. Other times it is that the foreign counterparty has no idea what the National E-Invoice System is and just wants to get a normal invoice by email. And yet for another, documents from abroad come through different channels and it is difficult to maintain order when part of the invoices goes to the KSeF, and some work outside the system.
In 2026, the topic is only gaining momentum, because the implementation of KSEF and the obligation to use KSEF force a new approach to invoicing in international transactions. Therefore, instead of generalities, we break it down into specific principles.
In the article we show:
— when the invoice for abroad is subject to Polish rules and then the KSeF system enters
— when the KSeF does not relate to the document, even though the sale is international
— what changes the fact that there is a foreign contractor on the other side, and what does not change anything
— how to approach the topic when there is a foreign entity and the thread of a permanent place of business arises
— how to organize the circulation, when part of the invoices are issued in the system, and part comes from outside it
We start from the basics. First, we figure out what exactly the KSeF system covers in 2026 and where its boundaries are. Then we move on to when invoices for abroad actually have to appear in the system, and when the topic is completely out of it.
KSeF in 2026. KSeF does not apply to all documents
“KSeF and foreign invoices” sounds like one question. In practice, these are always two questions at once. Whether the National e-Invoice System works at all in a given case and whether the invoice is subject to the obligation to use KSeF.
In 2026, the implementation of the KSeF will enter in stages. This means that some companies enter the KSeF system earlier, and some later. But regardless of the term, the principle is common. Not every document, which is colloquially called an “invoice”, needs to be created in it.
What does the system cover and what limits does it have in international trade
KSeF is a system for handling e-invoices in a structured form. If the document is accepted in the KSeF, the system assigns it an identifier and provides access to the invoice in the system. Such an invoice then appears in the invoice pool in KSeF.
In the context of international trade, two things are important:
— the fact that a foreign counterparty appears does not automatically make the document fall out of the system
— the fact that the contractor is outside Poland does not mean that he will receive invoices in the system. Often an invoice can be issued in KSeF, and the invoice is transferred to the recipient as established in the commercial relationship
Therefore, at the outset, it is worth separating the two issues. Obligation to issue an invoice in KSeF and the way in which the invoice recipient receives the document for their processes.
When the sale is out of the system, even though the document is created in the company
There are situations when KSeF does not apply to a given sale, despite the fact that the document is created in the company and looks like a classic invoice.
The most common example is selling to an individual. In such cases, issuing to KSeF is voluntary, and there is simply no obligation to issue invoices in KSeF.
Similarly, exclusions apply to parts of documents issued using cash registers. Including receipts with TIN up to PLN 450, which are treated as a simplified invoice. A transitional period is provided for such documents and, as a rule, they do not need to be issued in the KSeF until the end of 2026.
The conclusion is simple. The adjective “foreign” itself does not determine whether an invoice needs to be structured.
Transaction. How the type of sale affects the obligation on the part of the exhibitor
Whether or not you need to use KSeF is usually due to three elements:
— who is the exhibitor, i.e. which entity carries out the sale
— what is the transaction, i.e. what invoicing rules apply
— whether there is a connection with Poland on the part of the exhibitor, e.g. permanent place of business
In practice, the obligation depends on whether a given entity has the conditions for invoicing in Poland, i.e. whether it has a registered office in Poland or a permanent place of business and whether this permanent place actually participates in a given transaction. This distinction is crucial when a foreign entity is involved.
Only after these grounds have been established, it is possible to meaningfully answer the question of whether in a particular case it is necessary to issue a document to the counterparty in KSeF and whether we are talking about a standard invoicing in the system or a situation where the system does not apply.
Invoices for foreign contractors. When they need to be structured
In practice, the question is not “whether it is an invoice for abroad”, but: whether the issuance of an invoice is subject to Polish rules and whether the obligation to use KSeF operates at a given moment. Only then comes the topic of how such a document is supposed to reach the recipient.
Contractor. What determines the obligation on the part of the exhibitor
Whether you need to issue a document in KSeF depends primarily on whether you issue an invoice according to Polish regulations and whether you are covered by the obligation to issue invoices in the system.
Most often, three elements are decisive:
— the entity issuing the document. Does it work within the framework of the Polish billing rules
— transaction. What is its nature and does it require an invoice within the meaning of the VAT rules
— the moment of entry into the implementation of the KSeF. Is there an obligation on your part in a given period
An important distinction: the mere fact that the recipient is “foreign” does not automatically disable the KSeF system. If there is an obligation on your part and the document is issued according to Polish rules, such an e-invoice can be registered in KSeF as a structured invoice.
Foreign contractor. When to issue a document according to Polish rules
For many companies, the biggest surprise is this: an invoice for a foreign counterparty is often still issued “in Polish”, even if:
— currency is foreign
— the language of the document is English
— the VAT rate is 0% or there is an annotation about the settlement on the buyer's side
This means that in a B2B relationship, when you sell to the EU or outside the EU, the subject of invoices issued in KSeF can also concern you. Not because the recipient is in Poland, but because the rules for issuing an invoice are based on your status and type of transaction.
At the same time, there are situations when invoicing does not follow the “Polish path” and then KSeF does not apply to a given document. This may be the case if, in a particular case, the invoicing rules are derived from the country of taxation. This depends, among other things, on where the tax is located and whether you have a registered office in that country or a permanent place of business that participates in the sale in question.
In short: the thread of invoices issued for abroad must always be read through the prism of what regulations regulate the issue.
Foreign contractor. How to transfer a document when not using the system
Even if the document is created in KSeF, the foreign recipient will usually not receive the invoice directly from the system. KSeF is not a classic box for sending invoices to the world. It is a register and a structured issuance channel that provides access to the invoice within the powers granted.
Therefore, in a relationship with a foreign counterparty, two layers operate as standard:
— formal. structured invoice is issued and registered in the KSeF system
— communication. you transfer the invoice through a channel agreed with the recipient, most often as a visualization of the invoice in PDF
It is a good practice to clearly indicate in the body of the email or in the PDF itself the data that helps to link the document to the system:
— identification number, i.e. KSeF number
— date of issue of invoice
— information that it is a document generated as an e-invoice in the national system
As a result, the contractor gets a readable version for his circulation, and on your side there is a correct entry as an invoice in the KSeF.
Settlement of foreign invoices. EU, outside the EU and place of taxation
In the context of how KSeF works in international sales, the most confusion comes from two things being confused: who you issue the document to and where the tax is located. The latter often determines whether the issue goes according to Polish rules, and therefore whether the issue of invoicing in KSeF arises at all.
Foreign recipient and currency, language and data on the document
The fact that the recipient is outside Poland does not automatically force any “special” invoice format. In practice, an invoice issued to an EU or non-EU customer may have:
— foreign currency
— language version, e.g. English
— specific elements resulting from the type of transaction, e.g. an annotation on VAT settlement on the buyer's side
Such elements are normal and do not determine whether the document is to be “in the system” or “out of the system”. What matters here is whether there is an obligation on your part to issue an invoice according to Polish rules. If so, even with a foreign currency and language, it can still be an invoice to be issued at KSeF.
Here it is worth remembering one sentence: the commercial format and the language of the document are one thing, and the status of the document as an e-invoice in the system is another.
Entity. Who is the sales party and who is responsible for listing
In international transactions, it is crucial to determine who is the seller in a tax sense. Sometimes this is obvious and sometimes not, e.g. when invoices are issued on behalf of another entity or in a group structure.
If you are the seller and act as an obliged entity, the topic of listing in KSeF is on your side. Even if the recipient is foreign. If, on the other hand, the sale is carried out by another entity in the group and it is he who formally issues invoices, then the obligation may lie elsewhere.
It is also worth remembering that KSeF includes the issuance of an invoice in a structured form, but does not replace the contract or commercial conditions. The recipient of the invoice is to receive the document in a form that he can process. In practice, this often means PDF as a visualization of the invoice, even if the document is registered in the system.
Foreign entity. When there is an obligation on the part of a company outside Poland
This is where the most frequently searched topic arises: does a foreign company have to enter the mandatory KSeF.
Basically, what matters is whether a company outside Poland has a real connection with Poland in the field of invoicing, i.e. whether it has a permanent place of business activity here and whether this place participates in a given sale. If a foreign entity does not have a registered office or a permanent place of business activity in Poland, or has a permanent place but does not participate in a given transaction, then in many cases it may be out of the obligation to issue invoices to KSeF.
This distinction is crucial, because the mere presence of contractors in Poland does not determine the obligation. The most important thing is whether the way of conducting sales and issuing documents is “anchored” in Poland.
In practice, this means that before the question arises about whether invoices are registered in the KSeF, it is necessary to first establish the status of the entity and the place of taxation. Only after that it will be possible to answer whether such a sale requires issuing a document as an e-invoice in the system.
Handling of foreign invoices in KSeF. What goes into the system and what doesn't
In this section, we separate two tracks, which are often thrown into one bag. The first is when the document is issued and registered in the KSeF. The second is documents that function outside the system in international trade, because KSeF does not apply to their issuance.
How the recipient's number and document sharing works
If your sale is subject to an obligation, an invoice issued to a counterparty outside Poland may be issued directly to KSeF. After accepting the document, an identifier appears in the system, that is, the number of KSeF. This is important because the number is the best “glue” between what happens in the system and what the recipient sees.
In practice, it often works like this:
— the document is created as a structured invoice and is registered in the system
— then you prepare a visualization of the invoice for delivery to the recipient
— the invoice recipient gets the document outside the system, because he usually does not have access to the KSeF and will not download it there
It is worth calling it bluntly. KSeF allows you to issue and store documents, but it is not an “international mail” for all companies in the world. Therefore, in relations with abroad, the standard is a version made available outside the KSeF for circulation on the side of the counterparty, despite the fact that formally the document exists as an e-invoice in the system.
Invoice. What to convey to the recipient outside the system so that everything agrees
When a document is registered in the system and you send it to a foreign recipient outside the KSeF, it is important that the sent version is consistent with what is in the system. Most often we hand over:
— PDF as a readable invoice for the customer, i.e. visualization of the invoice
— information that the document was issued in the KSeF
— the date of issue of the invoice in accordance with the system
— identification number, i.e. KSeF number
This allows the invoice recipient to sign the document to their own processes. At the same time, the path in the system is sorted out on your side.
In addition, when there are several people in charge of invoicing in the organization, it is easier to verify that the invoice has been finally accepted and registered. In practice, the KSeF number and access to the invoice in the system confirm that the document “entered” the system circulation.
When the document is issued outside the system. The most common scenarios and effects
There are situations in which the invoice is issued outside the KSeF and this is correct, because the obligation does not work or the regulations provide for a different path. Examples of typical scenarios:
— sale to a natural person, where mandatory KSeF may not be
— cases in which there is no obligation to issue invoices in KSeF, because invoicing is carried out according to the rules of another country
— invoices in paper form, if a given type of document is not subject to an obligation or an exclusion is in effect
An important distinction: just because a document is “foreign” does not mean that it can be issued outside the system automatically. Similarly, the fact that a document is outside the KSeF does not mean that it has to be “sent” to the system. KSeF is not used to report such invoices. If an invoice is not issued in the system, there is usually no obligation to send to KSeF invoices issued through another channel.
Altera.app and integration with KSeF
This part is about what daily invoicing looks like when the KSeF system is running in the background, and at the same time you need to handle a foreign counterparty normally and transfer the document to its circulation. The point is that the issuance of an invoice does not turn into two separate processes.
How to use KSeF in Alterze.App in daily document flow
If a company has an obligation to use KSeF, one thing matters: not to issue invoices in KSeF on the principle “here the system, there the rest of your life”. En praktisk, a nêzikî ku hûn cîhek xebitandinê heye, û entegrasyona bi KSeF re di paşerojê de alîkariya we dike.
In such a model, the circulation looks simple:
— you issue a sales invoice in the same tool where you handle documents
— a document goes to the KSeF without the need to manually transfer data between systems
— after shipment, you see the status and have an organized history of invoices issued in one panel
—
This approach works especially well when there are a lot of documents in circulation and you want the e-invoice to be part of the process rather than a separate project to cover.
How to issue a document in KSeF for a client from abroad without additional steps
Con vendas internacional, la même scenario se: en el lado es una obligación, en el otro lado es un counterparty strano que no funciona en la realidade sistemica Polonesa.
Therefore, it is crucial to separate two things:
—
— in a business, it is necessary to provide the document so that the recipient of the invoice can use it immediately
In praxis, quando l'strumento è integrato nel XeF, è possibile eseguire come un singolo sequenza di azioni. Sending is on the side of the system, and handing over the invoice is on the side of communication with the customer. This is an important distinction in the topic of “KSeF and Foreign Invoices”, because many people assume that KSeF will “send” the invoice to the world. The system does not send it. The system registers it.
Invoice visualization. Prévisualisation dans le panel et à la version pour le recipient
Foreign audiences usually need something readable. Therefore, in addition to the fact that the invoice is registered in the system as a structured invoice, you also need a version that the recipient will actually read.
This is where the visualization of the invoice comes in, that is, the version to be sent, most often as a PDF. It is good if you have it on hand immediately after issuing, along with the key data:
— date of issue of invoice
— identifier, i.e. xEF number
— clear information that the document was issued in the KSeF and then transferred outside the KSeF for circulation on the part of the counterparty
L'effetto è che tutto il tuo secondo è legato in fatti nel sistema, e sul client del documento funziona normamente nel loro processo. Sin tradurre qu'è QSeF, senza “e dove devono fare clic su”, senza una volta di email extra.
Accounting service of documents from abroad in practice
In international trade, the most clutter is created not at the stage of whether a given invoice is in the KSeF system, but at the stage of circulation. Een e-invoicing van de documenten is uitgebracht en door de KSeF, en onderstaande uit de systeem. If these two streams are not arranged in one process, chaos quickly becomes.
How to organize documents from suppliers from abroad in one circulation
Invoices from a foreign supplier will not usually be recorded in KSeF, because KSeF is not used to report invoices issued by an entity outside the system. In practice, such documents go to the company through other channels, most often as PDF, less often as paper invoices.
In order to avoid diversions in the records, it is essential that, regardless of the channel, each invoice has one place in circulation and can be quickly assigned to the correct transaction. This is especially true when documents are issued to different departments or projects, and in the background there is a parallel obligation to issue invoices in KSeF on the sales side.
How to Combine International Sales with Billing and Records
When selling abroad, a critical point is to determine whether the listing is carried out according to Polish rules or according to the rules of another country. A partir de la tipo de tratación y qué entidade es la partita de vendas.
If you have an obligation to use the KSeF, then part of the sale to the EU or outside the EU may mean that the document has to be issued in the KSeF. At the same time, a foreign counterparty will usually not receive an invoice from the system. Therefore, a version of the e-invoice appears in the system for circulation on the recipient side of the invoice, and the transfer of the invoice takes place outside the system.
Tot ce doit être connecté que le données sur le document, l'entrée dans les registres et la status dans le KSeF ne se diverge à partir de l'autre, whether an invoice is issued in the KSeF or is issued outside the KSeF.
How to reduce document chaos when delivery channels are different
Two worlds operate in parallel in the company:
— sales invoices, which can be issued in KSeF and sent to the system
— purchase documents from abroad, which will not go to the KSeF, because the system does not include their issuance
Chaos most often comes from a blending of responsibility. Who is to collect the document. Who is to confirm that the invoice must be included in the records. Who assures that invoices sent abroad have consistent data, including the date of issue of the invoice and the information needed by the recipient of the invoice.
In addition, with international settlements, the topic returns to whether there is a foreign entity on the other side with a connection to Poland, for example through a permanent place of business. Sometimes this decides whether Polish invoicing rules come into play at all, i.e. whether KSeF applies to a given sale.
Resumen
We close the topic simply. Whether invoices for foreign counterparties are going through the National E-Invoice System does not depend on the recipient being “foreign”. It depends on whether you have an obligation to use KSeF, whether the transaction falls under Polish invoicing rules and who is the seller as an entity.
We also showed the other side of the coin. A document is issued as an e-invoice and goes to the KSeF, a foreign recipient usually needs a legible version for its circulation. Therefore, in practice, we combine two layers: formally the system, and operationally the transfer of the document in the agreed channel. Pir caran, wêneyek fatûreya bi daneyên sereke ye, tevî hejmara KSeF û tarîxa pirsgirêka fatûreyê.
If you want the topic of KSeF not to make invoicing abroad extreme sports, we get into it with Altera. Altera.app integrates with KSeF, organizes listings and statuses, and leaves you with what is important: normal work and normal business.
