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E-Invoicing Poland

After the E-Invoice has been sent, it needs to be approved by KSeF (Krajowy System e-Faktur) before processing can continue. As soon as efsta receives the state of the E-Invoice, it will be updated in the Portal, followed by error handling if necessary. The EFR will however respond immediately to the register request.

ESR.DD Fields​

In Poland there is no DDto field necessary, so you only have to specify DD in the transaction. Routing E-Invoices happens based on the TaxId. The invoice status can be requested from us, allowing it to be retrieved within a few minutes.

  • DD="PL-TEST" - Test environment, which does not require real access credentials and should be used exclusively with anonymized test data.
  • DD="PL-DEMO" - Pre-production (Demo) environment with realistic process flows and actual access credentials. Operates technically like the production system but has no legal effect. Only anonymized test data should be used.
  • DD="PL" - Live environment for processing real E-Invoices. All transactions are legally binding.
Example Request
{"Tra":
    {"ESR":
        {"D" : "2025-07-17T08:30:15", "DN" : "78312", "TL" : "001", "TT" : "1", "TN" : "1", "T" : "8.38", "Opr" : "101", "OprN" : "Mario Rossi", "OprTIN" : "xxx", "TP" : "Table 1",
        "DT" : "INVOICE", "DD" : "PL",
        "Ctm" : { "TaxId" : "PL1111111111", "Nam" : "The Sellercompany Incorporated", "Adr" : "1 Main street", "Adr2" : "Suite 123", "Zip" : "00-001", "City" : "Warszawa", "Ctry" : "PL"},
        "PosA" : [
            { "_" : "Pos", "PN" : "1", "IN" : "1001", "SKU" : "456487", "Dsc" : "Example Item", "TaxG" : "A", "Amt" : "3.98", "Qty" : "2", "QtyU" : "Pc.", "Pri" : "1.99", "Cat" : "10", "CatN" : "Example Category 10" },
            { "_" : "Pos", "PN" : "2", "IN" : "1020", "SKU" : "654854", "Dsc" : "Example Item", "TaxG" : "B", "Amt" : "1.50", "Cat" : "11", "CatN" : "Example Category 11" },
            { "_" : "Lin", "Dsc" : "Subtotal", "LAmt" : "5.48" },
            { "_" : "Pos", "PN" : "3", "IN" : "1030", "SKU" : "845868", "Dsc" : "Example Item", "TaxG" : "A", "Amt" : "2.90", "Cat" : "12", "CatN" : "Example Category 12"}
            ],
        "PayA" : [
            { "_" : "Pay", "Dsc" : "Example Payment", "PayG" : "cash", "Amt" : "10.00" },
            { "_" : "Pay", "Dsc" : "Example Change", "PayG" : "change", "Amt" : "-1.62" }
        ],
        }
    }
}

KSeF Portal Login​

Demo/Production Environment​

To access the Polish National E-Invoice System (KSeF) you must authenticate using one of the following secure methods:

Option A: Qualified Electronic Seal (recommended)

A Qualified Electronic Seal is a digital certificate issued to a company. It proves that electronic documents come from your organization. It is legally valid across the EU and the recommended way for companies to log in to KSeF without using a personal PESEL number.

  1. Purchasing
    Choose a certified provider, such as Certum or EuroCert, to purchase the electronic seal.

  2. Installing the certificate
    At Certum, it will be saved on a smart card inserted into a reader or in the SimplySign mobile app. You will also receive a signing application (e.g. proCertum).

  3. Login
    To access the KSeF system, choose the appropriate environment:

    Once the page opens click on "Authenticate in the National System of e-Invoices". Then submit your NIP, click "Next" and choose "Qualified Certificate".

    • The system will generate a login request file
    • Sign the file using your provider's application with your qualified seal
    • Upload the signed file to complete login
Option B: Trusted Profile

A free digital identity issued by the Polish government, only available if you have a PESEL number.

  1. Register online
    Go to https://pz.gov.pl/pz/register and fill in your details.

  2. Verify your identity
    Visit a Polish embassy or consulate within 14 days of registration. You have to bring your ID (passport or national ID card) to the appointment. After confirmation, your Trusted Profile is active and valid for 3 years.

  3. ZAW-FA
    You must submit a ZAW-FA to the tax office to associate your limited liability company to you.

  4. Login
    To access the KSeF system, choose the appropriate environment:

    Once the page opens, enter your NIP, click "Next", and select "Trusted Profile" as the login method. Sign in using your Trusted Profile credentials, then click ‘Sign’ to authorize and complete the login process to the portal.

Test Environment​

In the KSeF test environment, it is not necessary to use real authentication data. You can simulate the authentication process.

Test Enviornment Process

  1. Access the KSeF Test Environment

  2. Login context

    • Click on "Authenticate in the National System of e-Invoices"
    • Enter your NIP (Tax Identification Number) & click on "Authenticate"

  3. Authentication

    • Select "Qualified Certificate" as the authentication method
    • You’ll be asked if your certificate is a signature with a NIP or PESEL number. Select "Yes".
    • Select "Stamp with NIP" as identifier type and enter the same NIP number used at the beginning
    • Click "Authenticate to test application" to finish the process.

KSeF Token (deprecated)​

info

As of EFR version 2.7.9 the prefered way of authentication in the KSeF system via the EFR happens with an Authentication Certificate.

Legacy KSeF token guide

The KSeF Token is a string of alphanumeric characters (excluding punctuation marks), assigned to the taxpayer or authorized entity and their rights. It can be used to speed up and facilitate the process of logging into KSeF. Instead of authenticating each time, f.e with a qualified signature, you can generate a token and use that for the KSeF API authentication.
Your token authorizes efsta to issue E-Invoices on behalf of your company.

Generate Token

Once you are logged into the KSeF Portal, you will see the main dashboard.

KSeF Portal Overview

  1. Generate a token Go to the Tokens menu and choose to generate a new token with the role: issue invoices. Once the form has been filled in, click the "Generate Token" button.

Generate Token

  1. Copy the Token Copy the generated token and paste it into your configuration settings (see following step "Submit Token").

Token Generated

tip

There is no expiration date for the token, so you don't need to renew it.

If you want to revoke the token and remove efsta’s access to issue invoices for your company, you can do so in the token list by selecting the appropriate token and clicking "Revoke": Revoke Token

Submit Token

Finally, you have to paste the generated token in your configuration. You can achieve this either using the Portal or the EFR.

Portal

First, navigate to the appropriate register and click on the cloud icon to change your configuration. Then proceed to the "eDocument" tab and paste your token in the corresponding field.

Portal Configuration

EFR

Open the EFR and navigate to the KSeF tab. In the field "Token" you can paste the needed information.

EFR Configuration

warning

Once the token is submitted, E-Invoices are limited to that specific environment.
For example, if you generate a token from the KSeF demo portal, you can only perform DD="PL-DEMO" transactions.

KSeF Authentication Certificate​

The KSeF Authentication Certificate is assigned to the taxpayer or authorized entity and their rights. Your certificate authorizes efsta to issue E-Invoices on behalf of your company.

warning

Once a certificate is configured, E-Invoice transactions are restricted to that certificate's environment.
For example, if the certificate was issued in the KSeF Demo portal, it can only be used for DD="PL-DEMO" transactions.

Generate Certificate

Once you are logged into the KSeF Portal, you will see the main dashboard.

  1. Apply for the Certificate
    • Once logged in to the KSeF Taxpayer Application, open the Certificates section and apply for a certificate.

KSeF App Cert Page

  1. Select the Certificate Type
    • Select Authentication certificate from the available options.

KSeF App Cert Type

  1. Download and Convert Certificate

    • Download the generated .crt and .key files. Then convert them to .pfx format for use in the efsta Portal configuration:
    openssl pkcs12 -export -out auth_cert.pfx -inkey auth_cert.key -in auth_cert.crt
Install Certificate via efsta Portal

The efsta Portal only allows the simultaneous installation of both Authentication and Offline certificates, as both are needed in order for KSeF to properly function with the efsta infrastructure.

  1. Find the EFR by ID in the efsta Portal

    Portal EFR

  2. Open the KSeF Certificates section.

    Portal KSeF Cert section

  3. Upload the certificates Both Authentication certificate and Offline certificate simultaneously with the correct passwords.

    Portal KSeF Cert upload

The Portal pushes the certificate to the EFR automatically via the heartbeat mechanism. Once received, the Offline certificate is installed in memory and becomes available for offline signing.

KSeF Offline Certificate​

The KSeF Offline Certificate must be installed on the EFR via the efsta Portal. It is used to generate QR codes for offline printouts, for example when the POS is offline or the KSeF system is temporarily unavailable.

warning

The certificate is bound to a specific Tax ID. It will only be applied when the company Tax ID (Profile.TaxId) matches the Tax ID stored in the certificate. If they do not match, an error is returned.

Obtain the Certificate

Once you are logged into the KSeF Portal, you will see the main dashboard.

  1. Apply for the Certificate
    • Once logged in to the KSeF Taxpayer Application, open the Certificates section and apply for a certificate.

KSeF App Cert Page

  1. Select the Certificate Type
    • Select Offline certificate from the available options (name pending).

KSeF App Cert Type Offline

  1. Download and Convert Certificate

    • Download the generated .crt and .key files. Then convert them to .pfx format for use in the efsta Portal configuration:
    openssl pkcs12 -export -out offline_cert.pfx -inkey offline_cert.key -in offline_cert.crt
tip

Make note of the Tax ID (NIP) associated with the certificate — this must match the Tax ID configured in the EFR profile for the certificate to be applied.

Install Certificate via efsta Portal

The efsta Portal only allows the simultaneous installation of both Authentication and Offline certificates, as both are needed in order for KSeF to properly function with the efsta infrastructure.

  1. Find the EFR by ID in the efsta Portal

    Portal EFR

  2. Open the KSeF Certificates section.

    Portal KSeF Cert section

  3. Upload the certificates Both Authentication certificate and Offline certificate simultaneously with the correct passwords.

    Portal KSeF Cert upload

The Portal pushes the certificate to the EFR automatically via the heartbeat mechanism. Once received, the Offline certificate is installed in memory and becomes available for offline signing.

KSeF QR Codes​

KSeF requires a QR code on every fiscal document. The content of the QR code depends on whether the transaction was processed in online or offline mode.

Online Mode​

In online mode, a single QR code is produced. Scanning it redirects to the KSeF application where the submitted invoice data can be viewed.

Offline Mode​

In offline mode (for example when the POS is offline or the KSeF system is temporarily unavailable), two QR codes are produced:

  • OFFLINE: verification data for the offline transaction
  • CERTYFIKAT: certificate and issuer-identification data

Printing Behavior​

If a fiscal printer is configured, the EFR forwards the QR code data to the printer and the QR codes are printed on the fiscal document. The response then carries the QR code contents as plain Fis attributes named after the QR code (KSeF_Online_QR, KSeF_Offline_QR1, KSeF_Offline_QR2, see KSeF Response Fields), so the POS can store them or render its own invoice representation without printing them again.

If no physical printer is used (DO="noprint"), or the EFR could not print (no printer configured, printer error after the E-Invoice was accepted), the QR codes are returned as a Fis.Tag array and must be printed by the POS.

Interface rule

A Fis.Tag array in the response always means: the POS has to print these tags (see EFR API > Register). Once the EFR has printed the document itself, the tags are not returned as an array any more.

KSeF Response Fields​

info

Available with the EFR release 2.14

For every KSeF transaction that KSeF accepted (online) or that was queued for a later submission (offline), the Fis element of the TraC response contains the submission status and, when known, the KSeF invoice number. The fields are set independently of the printer connectivity and are returned through the normal register response path, both with a fiscal printer and with DO="noprint".

  • All fields are optional and backward-compatible: integrations that do not read them are not affected.
  • For transactions without DD (no E-Invoice) the Fis element is unchanged.
  • If KSeF or the EFR rejects the invoice, the transaction fails with an error and none of the fields are set.
  • KSeF_Status="ONLINE" is only returned together with KSeF_Number. If the E-Invoice was accepted but no KSeF number is known yet (see Talex), no KSeF field is set.
  • With a fiscal printer the printer fields (D, FN, DN, ZI, ID, see Printer Fields) come first in the same Fis element, followed by the KSeF fields.

Field Reference​

FieldTypeAllowed valuesOnline submissionOffline submissionReturned
Fis.KSeF_StatusStringONLINE, OFFLINEONLINEOFFLINEWhen accepted with a KSeF number or queued
Fis.KSeF_NumberStringKSeF invoice number assigned by KSeF, e.g. 1234563218-20260902-ABCDEF012345-67SetNot set — KSeF assigns the number only once the queued invoice has been submittedOnline only
Fis.KSeF_Online_QRStringContent of the online QR code (KSeF verification link)Set–Only after a printout by the EFR
Fis.KSeF_Offline_QR1StringContent of the first offline QR code (invoice verification)–SetOnly after a printout by the EFR
Fis.KSeF_Offline_QR2StringContent of the second offline QR code (certificate)–SetOnly after a printout by the EFR
Fis.TagArray of TagSee KSeF QR CodesOne entry: KSeF_Online_QRTwo entries: KSeF_Offline_QR1, KSeF_Offline_QR2Only when the POS has to print the QR codes

Each Tag entry carries the data of one QR code:

AttributeTypeDescription
LabelStringCaption printed next to the QR code: the KSeF number (online), Offline or CERTYFIKAT (offline)
ValueStringContent of the QR code (KSeF verification link)
NameStringKSeF_Online_QR, KSeF_Offline_QR1 or KSeF_Offline_QR2
TypeStringAlways QR

When the EFR printed the document, every tag becomes one Fis attribute: Tag.Name is the attribute name and Tag.Value its value. Label and Type are only needed for printing and are not returned in that case.

Printer Fields​

When the document was printed on the fiscal printer, the printer result is returned in the same Fis element, in front of the KSeF fields. Without a printout (DO="noprint", no printer configured, printer error) these fields are not set.

FieldTypeDescription
Fis.DStringDate and time of the printout as reported by the fiscal printer (only if available)
Fis.FNStringFiscal number of the document (also returned in ESR.FN)
Fis.DNNumberDocument number assigned by the fiscal printer
Fis.ZINumberDaily closure counter (Z-index) of the fiscal printer
Fis.IDStringSerial number of the fiscal printer

Online and Offline Behavior​

  • ONLINE: the E-Invoice was submitted to KSeF and accepted. KSeF_Number contains the number assigned by KSeF. The single online QR code is returned as KSeF_Online_QR attribute (printed by the EFR) or in Tag (to be printed by the POS).
  • OFFLINE: KSeF (or the efsta Cloud) was not reachable. The EFR fiscalized the transaction locally, the E-Invoice is queued (by the EFR or the efsta Cloud) and submitted automatically later, and the EFR returns the two offline QR codes as KSeF_Offline_QR1/KSeF_Offline_QR2 attributes (printed by the EFR) or in Tag (to be printed by the POS). KSeF_Number is not available in this case, because KSeF assigns the number only when the queued invoice is submitted (see Why does an invoice not immediately appear in KSeF?).
  • Talex (DD="PL-TALEX" / DD="PL-TALEX-TEST"): the E-Invoice is forwarded to the Taltax service, which submits it to KSeF in batches. The KSeF number is therefore not known when the EFR responds: the transaction succeeds with the warning #STATE_NOT_READY and no KSeF fields are returned. No QR codes are generated for Talex. If the Cloud is not reachable, KSeF_Status="OFFLINE" is returned without QR codes.

The offline QR codes require an installed KSeF Offline Certificate matching the configured Tax ID. KSeF_Status and KSeF_Number are returned regardless of the certificate.

What the POS Receives​

SituationWith fiscal printer (document printed by the EFR)With DO="noprint" or no printer configured
OnlinePrinter fields, KSeF_Status="ONLINE", KSeF_Number, KSeF_Online_QR. The QR code is printed on the document.KSeF_Status="ONLINE", KSeF_Number, Tag with KSeF_Online_QR. The POS prints the QR code itself.
OfflinePrinter fields, KSeF_Status="OFFLINE", KSeF_Offline_QR1, KSeF_Offline_QR2. Both QR codes are printed on the document.KSeF_Status="OFFLINE", Tag with KSeF_Offline_QR1/KSeF_Offline_QR2. The POS prints both QR codes itself.
Printer error after the E-Invoice was acceptedRC="OK", the printer error as Warning, no printer fields, KSeF_Status (and KSeF_Number when online) and the Tag array: the POS has to print the QR codes.–
Talex, accepted (KSeF number pending)Printer fields only, warning #STATE_NOT_READY.No Fis element, warning #STATE_NOT_READY.
Talex, offlinePrinter fields, KSeF_Status="OFFLINE".KSeF_Status="OFFLINE".

Printer fields: D (if reported by the printer), FN, DN, ZI, ID, see Printer Fields.

The QR code data is generated partly locally and partly in the efsta Cloud: in online mode the KSeF number and the QR link come from the Cloud, in offline mode the EFR calculates the invoice hash and the certificate data locally. Refunds, voids and similar corrections are not possible in offline mode; the transaction is rejected and no QR code is generated.

info

Up to EFR version 2.14.0 the response with a fiscal printer contained neither the KSeF fields nor the QR codes. Only DO="noprint" returned the QR Tag array.

Online Response Example — with fiscal printer

D is additionally returned in front of FN when the printer reports its date and time.

"Fis": {
    "FN": "I-649Z/001/1/340",
    "DN": 390,
    "ZI": 36,
    "ID": "ZBF 2101002096",
    "KSeF_Status": "ONLINE",
    "KSeF_Number": "9281838767-20260915-63E3EB000000-F3",
    "KSeF_Online_QR": "https://qr-test.ksef.mf.gov.pl/invoice/9281838767/15-09-2026/[hash]"
}
Online Response Example — DO="noprint"
"Fis": {
    "KSeF_Status": "ONLINE",
    "KSeF_Number": "9281838767-20260915-63EA7FC00000-ED",
    "Tag": [
        {
            "Label": "9281838767-20260915-63EA7FC00000-ED",
            "Value": "https://qr-test.ksef.mf.gov.pl/invoice/9281838767/15-09-2026/[hash]",
            "Name": "KSeF_Online_QR",
            "Type": "QR"
        }
    ]
}
Offline Response Example — with fiscal printer

KSeF_Number is not returned in offline mode. D is additionally returned in front of FN when the printer reports its date and time.

"Fis": {
    "FN": "I-649Z/001/1/343",
    "DN": 392,
    "ZI": 36,
    "ID": "ZBF 2101002096",
    "KSeF_Status": "OFFLINE",
    "KSeF_Offline_QR1": "https://qr-test.ksef.mf.gov.pl/invoice/9281838767/15-09-2026/[hash]",
    "KSeF_Offline_QR2": "https://qr-test.ksef.mf.gov.pl/certificate/Nip/9281838767/9281838767/[serial]/[hash]/[signature]"
}
Offline Response Example — DO="noprint"

KSeF_Number is not returned in offline mode. The transaction result carries ErrorCode="#OFFLINE" with RC="OK".

"Fis": {
    "KSeF_Status": "OFFLINE",
    "Tag": [
        {
            "Label": "Offline",
            "Value": "https://qr-test.ksef.mf.gov.pl/invoice/9281838767/15-09-2026/[hash]",
            "Name": "KSeF_Offline_QR1",
            "Type": "QR"
        },
        {
            "Label": "CERTYFIKAT",
            "Value": "https://qr-test.ksef.mf.gov.pl/certificate/Nip/9281838767/9281838767/[serial]/[hash]/[signature]",
            "Name": "KSeF_Offline_QR2",
            "Type": "QR"
        }
    ]
}

Timeout attributes​

The communication between the EFR and the Cloud can be adjusted using the Fiscal_timeout attribute.
The EFR can also send a timeout value to the Cloud that controls how long the Cloud waits for the KSeF system to respond via the eDoc_Timeout attribute.

KSeF Custom Invoice Number​

Invoices printed by the fiscal printer take their fiscal number from the printout (FI-{printer serial}/{TL}/{TT}/{printer document number}). For invoice documents the printer does not number, KSeF invoices (FakturaInfo/P_2) and invoice documents that are neither printed nor sent to KSeF, the EFR auto-generates the invoice number in the following format:

{type}-{efrNum}/{TL}/{TT}/{counter}

Where:

  • type is I for regular KSeF invoices, SI for simplified KSeF invoices, and NI for invoice documents (DT=INVOICE or NFS=INVOICE) that skip the fiscal printer via DO=noprint and carry no Polish DD (not sent to KSeF), for example a B2C invoice correction printed by the POS itself
  • efrNum is the EFR recorder number (with leading zeros stripped)
  • TL/TT is the transaction location and terminal identifier
  • counter starts at 1 and increments per transaction type, tracked separately per RN

To override this with a custom value, set ESR.InvoiceNumber in the transaction request. This is only applicable for invoice transactions (DT=INVOICE or NFS=INVOICE). For simplified invoices, the fiscal number is always auto-generated. When ESR.InvoiceNumber is provided, it is used directly as the invoice number: as P_2 for a KSeF invoice, or as the fiscal number of a non-printed invoice document.

Validation Rules​

A custom InvoiceNumber must satisfy both of the following conditions:

RuleConstraint
Maximum length256 characters
Allowed charactersAlphanumeric (a–z, A–Z, 0–9) and /, -, _, .

Spaces and any other special characters are not allowed. If either rule is violated, the EFR returns an error and the transaction is rejected.

Priority Logic​

ScenarioResolved Invoice Number
ESR.InvoiceNumber is provided and non-emptyCustom value (after validation)
ESR.InvoiceNumber is absent or emptyAuto-generated {type}-{efrNum}/{TL}/{TT}/{counter}
Example
{
  "Tra": {
    "ESR": {
      "DT": "INVOICE",
      "DD": "PL-TEST",
      "InvoiceNumber": "FV/2025-07-17/0042",
      "D": "2024-06-01T08:30:15",
      "TL": "001",
      "TT": "1",
      "TN": "21",
      "T": "399.00",
      "Opr": "101",
      "OprN": "Mario Rossi",
      "OprTIN": "xxx",
      "Ctm": {
        "CN": "12",
        "Nam": "Example Name",
        "Adr": "Example street 1",
        "Zip": "10115",
        "City": "Warsaw",
        "TaxId": "PL123456789"
      },
      "PosA": [
        {
          "_": "Pos",
          "PN": "1",
          "Dsc": "Example Item",
          "Amt": "399.00",
          "TaxG": "A",
          "Qty": "1",
          "QtyU": "Pc.",
          "Pri": "399.00",
          "Cat": "10",
          "CatN": "Example Category 10"
        }
      ],
      "PayA": [
        {
          "_": "Pay",
          "Dsc": "Example payment",
          "PayG": "creditcard",
          "Amt": "399.00"
        }
      ]
    }
  }
}
warning

The InvoiceNumber value is passed directly to KSeF as FakturaInfo/P_2. The integrator is responsible for ensuring uniqueness of the value within the KSeF system for the given taxpayer.

KSeF Metadata​

ESR.Metadata is an optional array that allows additional information to be attached to a KSeF transaction.

  • Each entry in the array must contain Key and Value
  • The Line field is optional and, when provided, must be an integer

Field Reference​

FieldDescriptionTypeMandatory
KeyMetadata key nameStringYes
ValueMetadata valueStringYes
LineOptional line referenceIntegerNo
Example Request
{"Tra":
    {"ESR":
        {"D" : "2025-07-17T08:30:15", "DN" : "78312", "TL" : "001", "TT" : "1", "TN" : "1", "T" : "8.38", "Opr" : "101", "OprN" : "Mario Rossi", "OprTIN" : "xxx", "TP" : "Table 1",
        "DT" : "INVOICE", "DD" : "PL",
        "Ctm" : { "TaxId" : "PL1111111111", "Nam" : "The Sellercompany Incorporated", "Adr" : "1 Main street", "Adr2" : "Suite 123", "Zip" : "00-001", "City" : "Warszawa", "Ctry" : "PL"},
        "Metadata" : [
            { "Key" : "ProjectCode", "Value" : "PRJ-001", "Line" : 1 },
            { "Key" : "ExampleKey", "Value" : "Example Value" }
        ],
        "PosA" : [
            { "_" : "Pos", "PN" : "1", "IN" : "1001", "SKU" : "456487", "Dsc" : "Example Item", "TaxG" : "A", "Amt" : "3.98", "Qty" : "2", "QtyU" : "Pc.", "Pri" : "1.99", "Cat" : "10", "CatN" : "Example Category 10" },
            { "_" : "Pos", "PN" : "2", "IN" : "1020", "SKU" : "654854", "Dsc" : "Example Item", "TaxG" : "B", "Amt" : "1.50", "Cat" : "11", "CatN" : "Example Category 11" },
            { "_" : "Lin", "Dsc" : "Subtotal", "LAmt" : "5.48" },
            { "_" : "Pos", "PN" : "3", "IN" : "1030", "SKU" : "845868", "Dsc" : "Example Item", "TaxG" : "A", "Amt" : "2.90", "Cat" : "12", "CatN" : "Example Category 12"}
            ],
        "PayA" : [
            { "_" : "Pay", "Dsc" : "Example Payment", "PayG" : "cash", "Amt" : "10.00" },
            { "_" : "Pay", "Dsc" : "Example Change", "PayG" : "change", "Amt" : "-1.62" }
        ],
        }
    }
}

Simplified Invoices​

Classification Logic​

The EFR classifies every KSeF transaction as either a regular invoice or a simplified invoice, based solely on the value of the DT and NFS fields. The transaction total (ESR.T) does not affect this classification.

ESR FieldsInvoice TypeKSeF RodzajFaktury
DT=INVOICE or NFS=INVOICERegularVAT
Neither set to INVOICE (including absent, empty, or any other value)SimplifiedUPR

A standard POS receipt sent with DD="PL" (or PL-DEMO/PL-TEST) and without DT=INVOICE or NFS=INVOICE will automatically be processed as a simplified invoice. No additional flags or configuration are needed.

Buyer Data Requirements​

FieldRegular InvoiceSimplified Invoice
Ctm.TaxIdRequiredOptional — if omitted, KSeF receives BrakID=1 (no buyer identification)
Ctm.NamRequiredOptional — included when provided
Ctm.AdrRequiredOptional — included when provided

If Ctm.TaxId is provided, it must follow the standard format (e.g. PL1234567890). If the country prefix is omitted, the EFR prepends PL (or Ctm.Ctry if set).

450 PLN Limit​

If the total (ESR.T) exceeds 450 PLN on a simplified invoice, the EFR returns a non-blocking warning:

#SIMPLIFIED_INVOICE_LIMIT — Transaction is a simplified invoice although the amount exceeds 450 PLN

This is a warning only — the transaction is still processed and submitted to KSeF. The POS can decide how to handle this (e.g. inform the operator, switch to a regular invoice by adding DT=INVOICE to the request).


Example: Simplified Invoice Request (Sale)

The absence of DT and NFS triggers simplified invoice processing. Only DD is required — Ctm.TaxId is optional.

<Tra>
    <ESR D="2025-07-17T08:30:15" DN="78312" TL="001" TT="1" TN="1" T="3.98" Opr="101" OprN="Mario Rossi" DD="PL">
        <Ctm TaxId="PL1111111111"/>
        <PosA>
            <Pos PN="1" Dsc="Example Item" TaxG="A" Amt="3.98" Qty="2" QtyU="Pc." Pri="1.99" />
        </PosA>
        <PayA>
            <Pay Dsc="Cash" PayG="cash" Amt="5.00" D="2025-07-17T08:30:15" />
            <Pay Dsc="Change" PayG="change" Amt="-1.02" D="2025-07-17T08:30:15" />
        </PayA>
    </ESR>
</Tra>

KSeF VAT Exemption Tax Groups (E, E2, E3)​

info

Supported since EFR version 2.9.0.

For VAT-exempt sales, KSeF needs to know the legal basis of the exemption. The EFR offers three exempt tax groups for this. They are all 0% / exempt — they only differ in the exemption reason reported to KSeF:

Tax group (TaxG)Legal basisWhen to use it
EPolish law (Art. 43 ust. 1, Art. 113 ust. 1 and 9, or regulations under Art. 82 ust. 3)Domestic Polish VAT exemptions — the majority of exempt sales.
E2EU VAT Directive 2006/112/ECThe exemption is claimed directly under the EU VAT Directive rather than a Polish provision.
E3Other legal provisionsAny exemption not covered by E or E2.

Just set the appropriate tax group on the exempt line; the EFR reports the matching legal basis to KSeF automatically.

warning

Only one exemption legal basis is allowed per E-Invoice, so a single invoice must not mix E, E2, and E3 across its lines.