UL 1998-2026 Ed.2 Mandates ASIL-B for BMS Software in North America

On May 10, 2026, UL Solutions officially published the second edition of UL 1998 (UL 1998-2026), introducing mandatory ASIL-B functional safety requirements—aligned with ISO 26262-6:2023—for battery management system (BMS) embedded software targeting the North American market. This update directly affects BMS software developers, automotive electronics suppliers, and OEMs engaged in vehicle electrification, particularly those exporting to or certifying products for the U.S. and Canada. Its significance lies not only in technical compliance but also in triggering upstream adjustments across development workflows, toolchain validation, and certification timelines.

Event Overview

UL Solutions released UL 1998-2026, Second Edition, on May 10, 2026. The standard requires all BMS embedded software intended for the North American market to comply with ASIL-B functional safety level per ISO 26262-6:2023 and to undergo toolchain credibility level (TCL) 3 verification. Enforcement begins December 1, 2026. Chinese BMS software development entities are explicitly noted as needing to upgrade their development processes and verification systems accordingly.

Industries Affected by Segment

BMS Software Development Firms

These firms are directly subject to the new requirement. Compliance now necessitates full integration of ASIL-B–level software lifecycle activities—including hazard analysis, safety goal decomposition, safety mechanism implementation, and bidirectional traceability—as defined in ISO 26262-6:2023. Impact manifests in extended development cycles, revised documentation standards, and mandatory TCL 3 validation for all tools used in safety-critical code generation, static analysis, and testing.

Automotive Tier-1 Suppliers Integrating BMS Software

Tier-1 suppliers incorporating third-party BMS software into their control units must now verify ASIL-B compliance and TCL 3 status of the supplied software toolchain—not just final functional behavior. This shifts responsibility for evidence collection (e.g., tool qualification reports, calibration records, configuration control logs) upstream to software vendors, increasing procurement due diligence and contract-level safety assurance clauses.

EV OEMs with In-House BMS Development

OEMs developing proprietary BMS firmware face internal process alignment requirements. Their software development standards, coding guidelines (e.g., MISRA C/C++), test coverage metrics (MC/DC), and independent verification & validation (V&V) plans must now be formally mapped to ASIL-B objectives. Internal audit scope expands to include toolchain credibility assessment for CI/CD pipelines and automated test environments.

Third-Party Certification and Testing Laboratories

Laboratories offering UL certification services must update their assessment checklists, auditor training modules, and reporting templates to reflect ASIL-B–specific artifacts and TCL 3 verification criteria. Capacity planning is affected, as ASIL-B assessments require deeper technical review than prior UL 1998 editions—and may involve cross-referencing ISO 26262-8:2023 for safety management system evaluation.

Key Focus Areas and Immediate Actions for Stakeholders

Monitor official UL guidance and transition clarifications

UL has not yet published detailed transition rules (e.g., grandfathering for legacy certifications, phased compliance paths). Stakeholders should track UL’s official announcements and technical bulletins issued before December 1, 2026, especially regarding interpretation of TCL 3 applicability to model-based design tools and cloud-hosted development platforms.

Prioritize ASIL-B readiness for North America–bound BMS software releases

For projects scheduled for launch or recertification between December 2026 and mid-2027, ASIL-B compliance must be embedded in current sprints—not deferred. This includes initiating safety plan reviews, updating configuration management systems to support safety artifact traceability, and selecting qualified tools early in the development cycle.

Distinguish between certification signal and operational readiness

The publication of UL 1998-2026 Ed.2 signals a formal shift in market access requirements—but does not automatically invalidate existing UL 1998-2022 certifications. However, any new submission after December 1, 2026 will be assessed against the new edition. Companies should treat this as a hard deadline for submissions, not a soft guideline.

Prepare documentation and supplier coordination protocols now

Developers must begin compiling evidence packages aligned with ISO 26262-6:2023 Annex D (software safety requirements specification) and Annex E (software architectural design specification). Concurrently, procurement teams should initiate alignment discussions with tool vendors to confirm TCL 3 eligibility and obtain updated qualification reports ahead of internal audits.

Editorial Observation / Industry Perspective

Observably, UL 1998-2026 Ed.2 represents more than a technical update—it reflects a convergence of North American safety expectations with global automotive functional safety practice. Analysis shows that UL’s adoption of ASIL-B (rather than lower ASIL levels or custom SIL equivalents) strengthens interoperability with ISO 26262–based OEM requirements and reduces fragmentation in supply chain safety validation. From an industry perspective, this is less a sudden regulatory shock and more a formalization of an emerging de facto standard. That said, the tight timeline—just under seven months from publication to enforcement—means the signal is already operational: readiness is no longer optional for market continuity.

Conclusion:

This update establishes a clear, non-negotiable safety benchmark for BMS software entering North America. It does not introduce novel safety concepts, but rather codifies ASIL-B as the minimum functional safety threshold for certification. Current understanding should recognize it as a binding compliance milestone—not a preview or proposal—and align development, procurement, and certification planning accordingly.

Information Source:

• UL Solutions official announcement: UL 1998-2026, Second Edition (published May 10, 2026)

Note: UL’s official transition policy, detailed TCL 3 implementation guidance, and clarification on legacy certification validity remain pending and warrant ongoing monitoring.