Overview
ISO/IEC 25390:2025 defines the normative specification for Simple Binary Encoding (SBE) - a binary message syntax used for financial information exchange. The standard specifies the wire format and the message schema for SBE. Although SBE is commonly used as a syntax for FIX messages, ISO/IEC 25390:2025 is explicit that SBE is not limited to FIX and can be applied to other low-latency financial protocols.
Key Topics
The standard covers detailed technical requirements and schema elements, including:
- Field model and metadata
- Semantic datatypes, encoding options, field presence and default values, and common field schema attributes.
- Primitive and composite encodings
- Integer, decimal, floating point, string (fixed/variable), raw data, MonthYear, date/time, local date/time.
- Encoding behaviour
- Byte order considerations, null/default handling, range attributes, and composite padding rules.
- Enumerations & choices
- Enumeration encoding, boolean representation, multi-value choice constructs.
- Schema and documentation
- Message templates, XML schema support, message schema structure, session protocol considerations.
- Design objectives
- Binary type system, design principles for deterministic, efficient wire formats, and documentation/format guidance.
These topics appear throughout the standard’s clauses (Scope, Objectives, Field Encoding, datatype-specific sections), providing implementers with both conceptual and normative requirements.
Applications
ISO/IEC 25390:2025 is aimed at systems where compact, deterministic, and high-performance message serialization is required. Typical applications include:
- Low-latency market data distribution and aggregation
- Order management systems, matching engines, and trade execution pipelines
- Financial middleware, gateways, and protocol adapters
- Risk, clearing, and back-office systems where binary efficiency improves throughput
- Schema-driven code generation tooling for messaging libraries
Using SBE helps reduce parsing overhead, minimize message size on the wire, and promote interoperable, schema-governed message exchanges.
Who Should Use It
- Protocol architects and systems engineers designing financial messaging systems
- FIX implementers and exchange/infrastructure vendors
- Developers building serialization libraries, code generators, or adapters
- QA and interoperability teams validating wire-format conformance
Related Standards (if applicable)
- FIX Protocol specifications (where SBE is used as an encoding option)
- Other ISO/IEC and industry standards governing financial message semantics and session protocols
Keywords: ISO/IEC 25390:2025, Simple Binary Encoding, SBE, FIX messages, financial information exchange, wire format, message schema, binary encoding, low-latency messaging.