peppol-sk

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A Java library for converting Peppol e-invoices (UBL 2.1 Invoice / CreditNote) into Slovakia Tax Data Documents (TDD) for tax reporting.

peppol-sk is part of my Peppol solution stack. See https://github.com/phax/peppol for other components and libraries in that area.

This project is work in progress and contains the version to be send out for member review - there might be future changes for the final data model for SK!

This contains a set of Java libraries. They are licensed under the Apache 2.0 license. The minimum requirement is Java 17.

The backing specifications are:

• SK TDD: https://docs.peppol.eu/tdd/sk/

Submodules

This project consists of the following submodules (in alphabetic order)

• peppol-sk-tdd - contains the main logic to create Peppol SK TDD documents based on the Peppol SK pilot documents as well as documentation
  • Main class to build a complete SK from scratch is PeppolSKTDD100Builder
  • To run the Schematron validation, use class PeppolSKTDDValidator
• peppol-sk-tdd-datatypes - contains the JAXB generated Peppol SK TDD data model
  • Main class to read and write TDD XML is PeppolSKTDD100Marshaller
• peppol-sk-testfiles - contains Peppol SK specific test files as a reusable component
  • Main class is PeppolSKTestFiles

Maven usage

Add the following to your pom.xml to use this artifact, replacing x.y.z with the real version number.

<dependency>
  <groupId>com.helger.peppol</groupId>
  <artifactId>peppol-sk-tdd</artifactId>
  <version>x.y.z</version>
</dependency>

Usage example

// Convert a UBL Invoice to a TDD document
TaxDataType tdd = new PeppolSKTDD100Builder ()
    .taxDataTypeCode (ESKTDDTaxDataTypeCode.SUBMIT)
    .reportingParty (participantID)
    .receivingParty (receiverID)
    .taxAuthorityID ("SK")
    .reportedTransaction (rt -> rt.initFromInvoice (invoice))
    .build ();

// Serialize to XML
String xml = new PeppolSKTDD100Marshaller ().setFormattedOutput (true).getAsString (tdd);

// Validate with Schematron
ISchematronResource schematron = PeppolSKTDDValidator.getSchematronSK_TDD_100 ();

The ReportedDocument is created for every TaxDataTypeCode, including D (DISREGARD), so all of its mandatory fields must be set. The ReportedDocument/UUID is calculated according to rule ID-BDID-01 from BT-34-1, BT-34, BT-3, BT-1 and BT-2. Leading and trailing whitespace is removed from these values for the calculation, and build() returns null if one of them is missing or empty. All other values are copied as is.

Building

This project requires Apache Maven 3.x and Java 17 for building. Simply run

mvn clean install

to build the solution.

News and noteworthy

v0.9.2 - work in progress

• PeppolSKTDD100ReportedTransactionBuilder.initFromInvoice and initFromCreditNote now find the cac:PartyTaxScheme for the VAT identifiers (BT-31, BT-48, BT-63) independent of the case and surrounding whitespace of the TaxScheme/ID, as the EN 16931 Schematron does. Previously a BIS3-valid TaxScheme/ID like vat or Vat lost the VAT identifiers in the TDD. See #10 - thx @FilipKovac

v0.9.1 - 2026-10-28

• Requires ph-commons 12.5.3
• Added taxPointDate (LocalDate) to PeppolSKTDD100ReportedTransactionBuilder. The value added tax point date (BT-7) of an Invoice or CreditNote is now taken over into ReportedDocument/cbc:TaxPointDate. See #5 - thx @FilipKovac
• Fixed an IndexOutOfBoundsException in PeppolSKTDD100ReportedTransactionBuilder.initFromInvoice and initFromCreditNote if the invoice period contains a tax point date code (BT-8). The value is now correctly taken over into ReportedDocument/cac:InvoicePeriod/cbc:DescriptionCode. See #6 - thx @FilipKovac
• PeppolSKTDD100ReportedTransactionBuilder.initFromInvoice and initFromCreditNote now take the VAT identifiers (BT-31, BT-48, BT-63) from the cac:PartyTaxScheme with TaxScheme/ID VAT, instead of always using the first one. Previously a Seller tax registration identifier (BT-32) listed first was reported as VAT identifier. A party without a VAT tax scheme now has no VAT identifier. See #7 - thx @FilipKovac
• Fixed PeppolSKTDD100ReportedTransactionBuilder.build () to write the payment instructions (BG-16) to the TDD. Previously the cac:PaymentMeans elements were collected but never emitted, so no TDD contained them. See #8 - thx @FilipKovac
• Added paymentMandateID (String) and payerFinancialAccountID (String) to PeppolSKTDD100PaymentMeansBuilder. The direct debit information (BG-19 with BT-89 and BT-91) of an Invoice or CreditNote is now taken over into cac:PaymentMeans/cac:PaymentMandate. See #8 - thx @FilipKovac
• PeppolSKTDD100ReportedTransactionBuilder now removes leading and trailing whitespace from the five values used for the ReportedDocument/cbc:UUID calculation (rule ID-BDID-01). A value that is empty after trimming is now treated as missing, so build () returns null instead of creating a deviating UUID. See #9 - thx @FilipKovac

v0.9.0 - 2026-10-22

• Requires ph-commons 12.5.2
• Added logHandler (ILogHandler) to PeppolSKTDD100Builder and all sub-builders. It receives the message of each missing or invalid required field (as error) when calling build (); the default handler logs to the logger of the builder class. Use ILogHandler.createForConsumer, ILogHandler.createForBiConsumer or ErrorListLogHandler to redirect the messages, and ILogHandler.createNoOp () to discard them. Call it first, because it is passed on to sub-builders created via lambda afterwards
• Added isEveryRequiredFieldSet (ErrorList) which collects the messages in an ErrorList, independent of the log handler
• Removed the public isEveryRequiredFieldSet () and isEveryRequiredFieldSet (boolean) methods; use isEveryRequiredFieldSet (ErrorList) or build () instead

v0.2.2 - 2026-09-23

• The tax exemption reason (BT-120) and tax exemption reason code (BT-121) are no longer copied into the invoice line VAT information (BG-30) and into the document level allowance/charge (BG-20, BG-21), because the SK TDD rules ibr-tdd-80 and ibr-tdd-63 forbid them there. See #4 - thx @mariansbr
• The tax category is no longer copied into the invoice line level allowance/charge (BG-27, BG-28), because the SK TDD rule ibr-tdd-60 forbids it there
• Added the new test invoice invoice/good/vat-category-AE.xml covering all of the above

v0.2.1 - 2026-08-12

• Added the mapping of tax exemption reason (BT-120) and tax exemption reason code (BT-121) in class PeppolSKTDD100TaxCategoryBuilder. See #3 - thx @vrbyjimmy

v0.2.0 - 2026-07-17

• Updated to ph-schematron v10.x
• Requires at least phive 12.0.2

v0.1.3 - 2026-03-11

• Updated to latest published Schematrons.

v0.1.2 - 2026-03-10

• Added support for participant identifier scheme 0245. See #1 - thx @vrbyjimmy

v0.1.1 - 2026-03-05

• Validating all output against all 3 layers of Schematron instead of just one
• Added the mandatory mapping of Reported Document / buyer name (BT-44)
• Added the optional mapping for price base quantity (BT-149)
• The builder class PeppolSKTDD100TaxSubtotalBuilder not also correctly uses the nested PeppolSKTDD100TaxCategoryBuilder builder class

v0.1.0 - 2026-03-03

• Initial version targeting Peppol SK member review TDD specs

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