The National e-Invoicing System in 2026 – what do you need to know to get started?
The year 2026 marks a time of colossal change for entrepreneurs. A great deal shifted during the first few months of the year – most notably, the vast majority of companies in Poland became required to switch to the National e-Invoicing System.
- On January 1, a module for submitting invoices with attachments via the e-US portal was launched.
- On February 1, the KSeF 2.0 system became mandatory for large enterprises and for all companies receiving VAT invoices.
- As of April 1, almost all remaining entrepreneurs are required to issue invoices via KSeF – with one minor exception.
Important!
The Ministry of Finance has provided for an additional deadline deferral for a small segment of businesses. The National e-Invoicing System (KSeF) remains optional for micro-enterprises with monthly turnover not exceeding PLN 10,000. These businesses will be required to issue invoices via KSeF starting January 1, 2027.
The deferral applies only to the issuance of invoices; all companies, regardless of their turnover, must already receive invoices via KSeF.
Who is exempt from KSeF?
Not sure if the obligation to use KSeF applies to your company? Check out the full list of exceptions—situations where you do not need to worry about the National e-Invoicing System (KSeF).
You do not have to issue invoices via KSeF if:
- You do not have a registered office or a fixed place of business in Poland (the existence of just one of these circumstances is sufficient to trigger the obligation to use KSeF).
- You do not have a registered office in Poland, but you do have a fixed place of business that is not involved in the invoiced supply of goods or provision of services.
- You are a taxpayer using special procedures:
- For entities based outside the EU that provide services to EU consumers and are registered in Poland for VAT purposes under the non-Union VAT scheme.
- For foreign entities registered for the special VAT scheme for international supplies. For foreign entities registered for the special scheme concerning the distance selling of imported goods.
- You are an entrepreneur from another European Union country, do not have a place of business in Poland, and meet all three of the following conditions:
- Your total annual sales across the entire EU (excluding VAT) do not exceed EUR 100,000 in the current or previous year.
- Your sales in Poland do not exceed the Polish exemption threshold for small businesses.
- You do not carry out supplies or services in Poland that are ineligible for the exemption based on business status, regardless of the turnover generated.
KSeF is not used to issue invoices addressed to private individuals not engaged in business activity, nor invoices concerning supplies of goods and services for which there is no obligation to issue invoices via KSeF – in accordance with the regulation issued by the Minister of Finance and Economy.
Important!
The list of supplies of goods and services exempt from the obligation to issue invoices via the National e-Invoicing System (KSeF) includes, among others:
- provision of toll motorway services,
- provision of passenger transport services,
- provision of air traffic control and supervision services.
However, if you do not qualify for any of the above exceptions, the obligation to issue invoices via KSeF applies to you right now.
What are structured electronic invoices?
What makes the introduction of KSeF such a major revolution—especially given the ongoing digitalization of recent years—is not merely the system’s mandatory nature, but above all its standardization. KSeF mandates a single invoice format: the structured invoice, which is effectively an .xml file.
What is the XML format?
XML – Extensible Markup Language – is a format that enables the recording and storage of data in a way that is readable and understandable to both humans and machines. Its distinguishing features are flexibility, independence, and machine-processability.
- In principle, the flexibility of the .xml format allows for the inclusion of custom tags and the definition of specific rules regarding document structure. While this is a crucial feature, it is less significant in the context of using KSeF; here, the format is predetermined, and businesses must adhere to it rather than modify it.
- XML’s platform independence means that files in this format can be read and edited regardless of the operating system or application being used. Users of macOS, Windows, or popular Linux distributions can all work with XML files seamlessly, without worrying about display or formatting errors. This is one of the format’s greatest advantages, making it ideal for business applications.
- .xml files are not designed for visual presentation; they do not take on an attractive visual form and are often not particularly easy for humans to read. However, they excel at enabling the data they contain to be processed by various tools – including KSeF-compatible applications.
Full digitalization is already here – what benefits does it bring?
In B2B transactions, traditional paper invoices and electronic invoices (in PDF format) have become a thing of the past. Document workflows in Poland are shifting toward standardization – specifically, issuing invoices in a single format (XML) with a predefined structure.
While this structure is subject to change (the FA (3) version is currently in use), any modifications apply immediately to all users of the National e-Invoicing System (KSeF). Consequently, there is no risk of a situation where a business issues a structured electronic invoice compliant with the latest schema, only for the recipient to be unable to process it due to using an outdated version.
Another benefit of implementing KSeF is the automatic verification and validation of data contained in structured invoices. Every issued invoice is transmitted to government servers, where the accuracy of the entered data – or, more precisely, its compliance with the required structure – is checked.
Important!
The system does not automatically detect errors; it merely checks whether the submitted files comply with the schema (logical structure). This means that common errors – such as entering an incorrect recipient account number or specifying the wrong quantity of goods – will not be detected. The person issuing the invoice is personally responsible for ensuring the accuracy of this information.
What errors does the automatic invoice verification in KSeF detect?
During verification, the system may report, among other things:
- unfilled mandatory invoice fields,
- non-compliance with the FA (3) schema,
- inconsistencies between the Tax Identification Number (NIP) and/or counterparty details and the information in the VAT taxpayer register,
- VAT calculation errors,
- the presence of prohibited characters (certain special characters, HTML characters, etc.),
- a lack of authorization to issue invoices,
- an invalid document signature.
Important!
Tools for issuing invoices in KSeF (both commercial and free ones provided by the Ministry of Finance) enable local validation—a preliminary check that flags errors similar to those identified during verification on government servers. Use this feature to eliminate errors before issuing an invoice in KSeF.
KSeF invoicing applications
To correctly issue an invoice within KSeF, you first need to obtain the appropriate software. Commercial solutions such as iFirma, Faktura.pl, and wFirma are available on the market.
However, it is worth noting that the Ministry of Finance and Economy has made two applications available that taxpayers can use free of charge to issue invoices via the National e-Invoicing System (KSeF). These are:
- KSeF Taxpayer Application 2.0,
- e-Mikrofirma.
How to issue an invoice in KSeF step by step?
It is time to move on to how to issue an invoice in KSeF.
Logging in to the KSeF Taxpayer Application
To get started, log in to the KSeF Taxpayer Application using one of the following methods:
- mObywatel app,
- online banking,
- e-ID card,
- Trusted Profile,
- eID.
Once logged in, you will see a panel on the left with five categories:
- Invoices – here you can issue VAT and RR invoices, upload invoices, and view the list of documents.
- Session History – allows you to view past sessions and actions performed on your company’s KSeF account.
- Permissions – a panel for managing permissions. Here you can add an administrator, grant or revoke permissions for specific individuals, and check your own permission level.
- Tokens – here you can generate a new token if needed or view the list of tokens.
- Certificates – select this category to apply for a certificate or view the list of certificates.
Issuing invoices in KSeF
From the menu on the left, select the “Invoices” category, and then the “Issue VAT invoice” option.
Step 1: Select the invoice type
The Taxpayer Application allows for the issuance of the following types of invoices:
- standard,
- advance payment,
- final settlement,
- corrective.
In most cases, selecting the “standard” type will suffice. Once this option is selected, another field will appear where you can choose the specific form type.
Step 2: Select the form type
The Taxpayer Application offers a choice between a simplified form and an extended form. This choice depends on your individual needs.
In most cases, the simplified form will be suitable – especially for standard B2B transactions. However, it is worth examining the extended form as well to ensure that none of the fields it contains are required for the specific type of operation you wish to document with the invoice. Selecting this option will reveal a further field where you can choose the form type.
Step 3: Select annotations (optional)
Below, you will find the “Annotations” section. This is an optional step, but it is worth noting. The “Annotations” section contains four items:
- supply of goods or services exempt from tax under Art. 43 para. 1, Art. 113 paras. 1 and 9, or regulations issued pursuant to Art. 82 para. 3 or other provisions,
- split payment mechanism,
- cash accounting method,
- margin scheme.
Select the annotations that apply to your situation and proceed to the next step.
Step 4: Fill in the invoice details.
In the “Invoice details” section, fill in the following in order:
- invoice number,
- document issue date,
- place of issue (optional),
- date or period covered by the invoice,
- date of delivery of goods or performance of service,
- invoice price (net/gross),
- currency codes.
Step 5: Enter the items.
Enter the goods sold or services provided into the invoice here. For each item, you can specify:
- the name of the good or service,
- quantity,
- unit of measure,
- net unit price,
- net sales value – this will populate automatically based on the previously entered quantity and net unit price,
- tax rate – select from the drop-down list.
The Taxpayer Application will calculate the total amount due.
Step 6: Fill in the remaining information.
After filling in the line items, proceed to the sections below. Here, you can – among other things – add extra sections to the invoice.
The first of these is the Payment section, where you can specify the payment due date, status, and method. You can also add a description of the payment terms and include a link to a payment gateway and/or the account number for the payment. Additionally, you can specify a factor’s account number or a cash discount (skonto) here.
These options are optional; you can choose to include some, all, or none of them.
To proceed to the next stage, click the “Next” button.
Step 7: Enter the seller’s identification details.
In this section, you will find space for the seller’s identification details:
- Tax ID (NIP),
- full name or company name,
- address,
- contact details (optional).
To proceed to the next step, click the “Next” button.
Step 8: Enter the buyer’s identification details.
The next section allows you to enter information regarding the purchaser (invoice recipient):
- select the identification details (Tax ID, EU VAT number, other tax identifier, or no identifier),
- full name or company name,
- address,
- contact details (optional),
- purchaser status (subsidiary or VAT group member – select YES or NO).
To proceed to the next stage, click the “Next” button.
Step 9: Preview the issued invoice.
Here, we can:
- issue an invoice,
- download it in .pdf or .xml format,
- opt out of issuing an invoice,
- preview the invoice.
Naturally, we choose the last option, allowing us to check that all the entered data is correct and to verify the invoice’s technical accuracy.
Step 10: Issue an invoice in KSeF.
Click the “Issue invoice” button and wait for the system to finish processing the invoice. A notification will then appear on the screen stating: “Completed successfully. Your e-invoice has been successfully issued and will soon be available on the invoice list.”
At this point, the invoice will also be assigned a KSeF number, which will serve to identify it.
How do I issue another invoice?
Immediately after issuing a structured invoice, a “Create another invoice” button will appear. Clicking it takes you back to the start of the KSeF invoicing process. However, you do not need to enter all the data from scratch. To speed up the process, follow these steps:
- Select the “Invoices” section from the left-hand menu, then choose “Invoice list.”
- Select a previously issued document from the list.
- Click the relevant KSeF invoice number and select the “Issue similar invoice” option. This gives you access to a pre-filled form containing data that exactly matches the previously selected invoice.
- Modify the invoice details to reflect the next transaction you wish to document.
KSeF and foreign invoices – how to settle accounts with contractors from outside Poland?
The National e-Invoicing System (KSeF) is a solution designed for invoice management by Polish taxpayers. This means that foreign entities cannot use KSeF unless they hold a Polish Tax Identification Number (NIP) and maintain a fixed place of business in Poland.
So, what should you do if you are a Polish VAT taxpayer but your counterparty is a foreign company without access to KSeF? You should issue the invoice in KSeF as usual and transmit it to the counterparty via another method – for example, by email.
How do I issue foreign invoices in KSeF?
First: issue the invoice in KSeF as usual (following the step-by-step process discussed earlier in this article).
Second: share the issued document with the counterparty—for example, as a PDF file containing a QR code that allows them to view the invoice.
Important!
A QR code is a mandatory element of an invoice for international transactions; it allows recipients to view the document without accessing the KSeF and to verify the invoice’s KSeF number (identification number).
Foreign purchase invoices and KSeF
What if you are the buyer and the seller is a foreign company? In this case, nothing changes. Invoices received from foreign sellers do not appear in the KSeF system; after all, foreign counterparties do not have the ability to issue such invoices. You therefore need not worry about adding yet another obligation to your already extensive list.
You will typically receive an invoice from abroad via email or access it through a customer portal provided by the supplier. Simply record the document in your accounting system and then account for the VAT using the reverse charge mechanism.
Invoices in KSeF: most common errors
The scope of changes introduced by the National e-Invoicing System (KSeF) leads many entrepreneurs to make errors. The most common mistakes—and thus those requiring particular attention—include:
- failure to authorize within KSeF,
- entering an invoice date in an incorrect format,
- applying an incorrect VAT rate,
- entering an incorrect Tax Identification Number (NIP),
- attempting to issue a corrective invoice without providing details of the original invoice being corrected,
- attempting to issue an invoice in KSeF that is not subject to the mandatory KSeF submission requirement,
- attempting to issue an invoice duplicate in KSeF.
Summary
The process of issuing an invoice via KSeF – while comprising as many as ten steps – is not actually overly complicated. However, it does require attentiveness, focus, and verification of the data being entered. This is particularly important when issuing a subsequent invoice using data from a previous document; it is easy to inadvertently leave pre-filled information in the form that is actually incorrect because it pertains to a different invoice.
Nevertheless, issuing each subsequent invoice should become noticeably easier over time. After all, practice makes perfect – even when using KSeF.
Frequently Asked Questions
What is needed to issue an e-invoice in KSeF?
If your company is required to issue invoices via the National e-Invoicing System (KSeF), you can use the free government KSeF Taxpayer Application. It allows you not only to issue and submit invoices to the system but also to manage user permissions, view a list of issued invoices, download them, or apply for a new certificate.
You can also use commercial software integrated with the National e-Invoicing System.
How to issue an e-invoice in KSeF step by step?
Log in to the Taxpayer Application and select the “Issue VAT invoice” option, then:
- Select the invoice type (standard, prepayment, settlement, or corrective).
- Select the form type (simplified or detailed).
- Select the appropriate annotations (split payment, cash accounting method, margin scheme, or tax exemption).
- Fill in the invoice details (invoice number, date of issue, date of delivery of goods, etc.).
- Enter the line items (goods sold or services rendered).
- Fill in the remaining information (payment details, factor’s account number, early payment discount).
- Fill in the seller’s identification details (Tax ID, company name, address).
- Enter the buyer’s identification details (as above).
- Preview the generated invoice.
- Issue the invoice in KSeF.
How do I issue invoices for foreign buyers in KSeF?
We issue invoices for foreign buyers in the KSeF system just as usual. However, it is important to remember that the National e-Invoicing System (KSeF) operates only in Poland, and foreign counterparties do not have access to it. Therefore, an invoice issued in the system must be transmitted to the foreign buyer using a traditional method – most commonly via email as a PDF file containing the QR code.
Should an invoice I receive from a foreign vendor be submitted to the KSeF?
No. Record the invoice received from the foreign seller in the system exactly as you did before the introduction of the National e-Invoicing System.
