ISO IEC 25390-2025 PDF

Full title and description

St ISO IEC 25390-2025 — Information technology — Financial information exchange — Simple Binary Encoding. This international standard specifies the Simple Binary Encoding (SBE) wire-format and message schema used for low-latency financial information exchange (commonly used with FIX messaging but applicable more broadly). It provides the normative encoding rules, data types, message framing and schema definition needed to implement interoperable, efficient binary messaging for trading and market-data systems.

Abstract

ISO/IEC 25390:2025 defines the normative specification for Simple Binary Encoding (SBE). The document covers the encoding (wire format), message schema definitions, data-type representations, versioning and backward-compatibility considerations, and conformance guidance. SBE is intended to provide a compact, deterministic binary serialization format optimized for extremely low-latency financial messaging while remaining usable outside FIX-based environments.

General information

• Status: Published
• Publication date: 23 April 2025
• Publisher: ISO/IEC (joint publication by the International Organization for Standardization and the International Electrotechnical Commission), prepared under ISO/IEC JTC 1
• ICS / categories: 35.240.40 (Information technology — Banking/financial systems)
• Edition / version: Edition 1.0 (2025)
• Number of pages: 55

Scope

This standard specifies the Simple Binary Encoding (SBE) syntax and rules for encoding financial messages into a compact binary wire format. The scope includes: definition of primitive and composite data types for SBE; message and schema structure; field presence and default-value handling; message framing and length-prefixing; versioning and schema evolution rules to support backward and forward compatibility; and normative conformance requirements. The standard is intended for implementers of high-performance trading systems, market-data distribution, gateways and middleware that require deterministic, low-overhead message serialization.

Key topics and requirements

• Normative specification of the SBE wire format and encoding rules.
• Definition of primitive data types, composite types, and length/endianness rules for binary fields.
• Message and schema model: message blocks, fields, repeating groups and variable-length fields.
• Schema versioning and compatibility rules to manage evolution of messages safely.
• Conformance and interoperability requirements for producers and consumers.
• Performance and implementation guidance for low-latency systems (alignment, padding, memory layout).
• Examples and canonical encodings illustrating common financial message patterns.
• Recommendations for mapping FIX semantics (where used) to SBE schema constructs.

Typical use and users

Primary users are financial technology implementers: trading firms, exchanges, market-data vendors, electronic liquidity providers, and middleware vendors. Typical uses include high-performance trading engines, market-data distribution networks, FIX gateways, order-routing systems and any application requiring compact, deterministic binary messaging for financial transactions and real-time market information.

Related standards

Related documents and families include the FIX protocol specifications (commonly used together with SBE for low-latency FIX message carriage), ISO 20022 financial messaging guidance (broader financial message models), and general information-technology standards for security and interoperability such as ISO/IEC 27001 (information security management). Implementers should also consider other ISO/IEC JTC 1 standards addressing serialization, protocol design and testing when integrating SBE into larger systems.

Keywords

Simple Binary Encoding, SBE, financial messaging, FIX, wire format, binary serialization, low-latency, market data, schema versioning, ISO/IEC 25390:2025

FAQ

Q: What is this standard?

A: ISO/IEC 25390:2025 is the international standard that defines Simple Binary Encoding (SBE), a compact binary wire-format and schema model for financial information exchange.

Q: What does it cover?

A: It covers the normative encoding rules, data-type definitions, message and schema structure, framing, versioning/compatibility rules, conformance requirements and implementation guidance for high-performance binary messaging.

Q: Who typically uses it?

A: Software developers and architects at trading firms, exchanges, market-data providers, FIX gateway vendors and middleware/latency-sensitive system integrators who need efficient, deterministic serialization for financial messages.

Q: Is it current or superseded?

A: This is the first edition, published 23 April 2025. It is current as of its publication date; users should check for amendments or later editions if long-term maintenance or new features are required.

Q: Is it part of a series?

A: ISO/IEC 25390:2025 is a standalone international standard focused on SBE, but it is part of the broader set of information-technology and financial messaging standards maintained under ISO/IEC JTC 1 and is commonly used alongside FIX protocol specifications and other financial-message frameworks.

Q: What are the key keywords?

A: SBE, Simple Binary Encoding, FIX, financial messaging, binary wire format, low-latency, schema, ISO/IEC 25390:2025.