Faktoo FAQ

The ISDOC (Information System Document) format is an open structured document format based on XML and designed primarily for the electronic exchange of business documents. It is commonly used in the Czech Republic, but also in Slovakia, for sending invoices and other business documents to companies and government authorities.

The format was developed to increase efficiency by automating document processing, ensure accuracy and reduce errors in transactions, in compliance with legal requirements and tax regulations. Importing an ISDOC document replaces manually transcribing data into an accounting or other system.

ISDOC files usually present in machine-readable form the data provided on commercial documents, such as entity identification data (company names, ID numbers, addresses), document metadata (invoice number, order number, date of execution, etc.), item lists (goods and services invoiced), summary data (total amount, tax rate and amount).

The administration of the format, especially for the Czech environment, is provided by the Department of the Chief Architect of eGovernment of the Ministry of the Interior of the Czech Republic in the website section focused on ISDOC. For the Slovak environment, the slovensko.digital initiative develops the format in cooperation with ISDOC economic software producers.

Most accounting and economic software (ERPs) used in the Czech Republic can invoice in the ISDOC format, incl. Money S3, Pohoda, Helios, ABRA Gen, FlexiBee and many others. ISDOC is also supported by common invoicing systems such as iDoklad or Fakturoid. Especially from 2024 onwards, the format is also supported by a significant part of Slovak ERP. Individual software can also import the format, although not yet fully unattended and for all possible document variants.

An ISDOC is a machine-readable XML document, normally with a .isdoc or .xml extension, and is not in itself completely human-friendly. It can therefore be sent e.g. as a separate file next to a PDF version of the invoice with a preview (print) version of the invoice. However, since it is not entirely practical to separate structured and user-readable data into separate files, two technical solutions for encapsulating them have been developed. ISDOC.PDF is a PDF document (i.e. human-readable and printable) into which ISDOC version 6.0.2 is directly embedded. ISDOCX is an older variant of encapsulating structured data and PDF into a single file with ZIP compression. Compared to ISDOC.PDF, it is less user-friendly, mainly because it does not offer the possibility of easy preview in common means (PDF reader) and probably for this reason it never caught on much in practice.

ISDOC.JSON is an informal representation of ISDOC format data in JSON notation. Because implementing inputs and outputs in JSON format is usually easier than implementing inputs and outputs formatted as XML, ISDOC.JSON is useful, for example, when developing customer-specific software to generate outgoing business documents or, conversely, to automatically process incoming business documents.

JSON (JavaScript Object Notation) is a lightweight textual format for data exchange compared to XML, which is easy to compile and retrieve by computer, is economical in terms of size requirements, and is also relatively human-readable. Because of these advantages, it is widely used to represent structured data, especially in web applications, APIs (application programming interfaces), and configuration files.

EDIFACT (Electronic Data Interchange For Administration, Commerce, and Transport) is an international standard for electronic data interchange (EDI) that defines the syntax and structure of business documents exchanged between organizations. It was developed by the United Nations (UN) under the UN/EDIFACT (United Nations/Electronic Data Interchange For Administration, Commerce, and Transport) initiative. It is not a single document format, but rather a comprehensive framework for structuring data. It is not based on XML or JSON, and the data notation format is proprietary. Because of its considerable complexity, EDIFACT is challenging to implement.

The Universal Business Language (UBL) is an open standard based on XML for the exchange of business documents such as invoices, credit notes, purchase orders, delivery notes and more, managed by the non-profit Organization for the Advancement of Structured Information Standards (OASIS). Unlike local formats (e.g. ISDOC for use in the Czech Republic and Slovakia), it has been designed for international use and is therefore not tied to any particular region or legal system. The UBL 2.1 version is one of the formats for electronic invoices according to the European standard (EN 16931) and together with the EDIFACT format is one of the recommended formats under European legislation. As it is a very complex format, its full implementation in software is challenging.

The faktoo service has been developed as a widely available node in the e-invoice ecosystem, usable by both human users and electronic systems via its API (application programming interface), with the vision of gradually extending its functionalities so that as many entities as possible, including sole traders and small businesses, can benefit from the advantages of machine-readable data exchange.

The faktoo web interface can (1) display ISDOCX / ISDOC.PDF / PDF document pair and ISDOC in parallel view (part of the screen PDF preview, part of the screen structured data), (2) create or edit ISDOC in an interactive form, (3) validate ISDOC against XML Schema, Schematron rules according to ISDOC standard and extension rules defined in the system, (4) perform ISDOC format conversions.

Faktoo allows to (1) separate PDF and ISDOC from ISDOCX and, in turn, merge PDF and ISDOC into ISDOCX, (2) separate PDF and ISDOC from ISDOC.PDF and merge PDF and ISDOC into ISDOC.PDF, (3) convert ISDOC to UBL, (4) convert ISDOC to ISDOC.JSON and back.

In particular, after registration, you can connect disk storage and then work on the contained files. Currently Google Drive, Microsoft OneDrive or others supporting the WebDAV protocol are supported. Registration is also necessary to use the faktoo API.

All validation, conversion, transformation functionalities over individual documents and data from the connected repository can be called via API. Processing results can be stored in the repository, prepared for retrieval via API or, for example, sent to a target email address. By deploying the API on incoming invoices, it is possible, for example, to automatically load their data into the ERP, implement specific rule processing, including approval. For issued invoices, for example, your simple automated invoicing system can generate simple JSON files, pass them to Faktoo, have them converted to full ISDOCs and then send them out.

Sure, more functionalities are under development such as custom validation rules, connectors for integration into popular economic software (validation against dials, better imports, user-defined actions in relation to rules, etc.), more format conversion directions. Stay tuned!