Navigating Urgent E-Invoicing Mandates: December 2025 Regulatory Alert

As we step into 2026, I'm watching businesses around the world still catching their breath from the regulatory whirlwind that closed out 2025. October and November brought significant developments across Europe and Asia, setting the stage for accelerated e-Invoicing compliance efforts. While December is typically a quiet month for regulatory updates, that wasn’t the case year. The las month of the year kept the momentum going with new mandates and critical refinements.  Here’s what changed and what it means for your compliance strategy in 2026.

New E-Invoicing Mandates & Major Rollouts

Slovakia

The Slovak parliament approved a draft law introducing mandatory B2B e-invoicing and real-time reporting obligations. While effective dates will be confirmed when publication of the final law, this development signals a major shift toward digitization. Expect technical specifications for invoice issuance, transmission, and reporting in coming regulations.

Nigeria

OpenPeppol, in cooperation with Nigerian authorities, drafted the Peppol International (PINT) Billing and Self-Billing specialization for Nigeria. The review period for stakeholder feedback closed on 5 January 2026. This is a big step toward standardising e-invoicing in Nigeria and aligning with global interoperability frameworks. Businesses operating in Nigeria watch this closely and prepare for technical integration requirements once the specification is finalised.

E-Invoicing Mandate Timeline Updates

France made it clear: no more delays to the rollout schedule for e-invoicing reform. Key milestones include:

• 14 January 2026: End of testing phase for Approved Platforms.
• End of February 2026: Launch of production pilot phase.
• May 2026: Opening of qualification environment for the public sector.  

Additionally, France and Germany jointly published Factur-X 1.08 / ZUGFeRD 2.4, a harmonised hybrid format aligned with EN 16931, effective 15 January 2026. This update supports SMEs and VSEs with improved interoperability and compliance.

Belgium went live on 1 January 2026 with mandatory B2B e-invoicing, while introducing practical refinements:

• Scope clarification for non-established VAT entities.
• Relief for suppliers where buyers cannot receive structured invoices.
• A grace period until 31 March 2026 for certain breaches, provided businesses demonstrate reasonable compliance efforts.  

Belgium's trying to make the transition easier without pushing back the deadline.

Spain approved a one-year delay for the Verifactu requirement:

• New obligation dates: 1 January 2027 for large taxpayers and 1 July 2027 for SMEs and self-employed workers.  

This gives businesses additional time to adapt systems, though formal legislation is pending.

Poland published two key regulations effective 1 February 2026:

• Confirming exempt transaction categories under KSeF 2.0.
• Aligning invoice issuance requirements with structured e-invoicing rules. Additionally, token generation functionality for KSeF authentication went live on 10 December 2025, supporting secure access to the platform.

Latvia adopted Regulation No. 749, establishing a framework for e-invoicing and e-reporting:

• Mandatory technical standards: UBL 2.1 and PEPPOL BIS Billing 3.0.
• Strict submission deadlines: E-invoices must be reported to the State Revenue Service within five working days.
• Implementation timeline:
  • 1 January 2026: E-reporting mandatory for B2G and G2G transactions.
  • 1 January 2028: E-reporting and e-invoicing mandatory for B2B transactions.

Technical & E-Invoicing Compliance Updates

Serbia rolled out significant e-invoicing updates:

Amendments to the Law on E-invoicing effective 12 December 2025, mandating electronic VAT registration and expanding SEF functionality.

Release of SEF platform version 3.16.0 in both test and production environments, adding stricter API validations, new invoice fields, and enhanced UI features.

Turkey updated its e-Archive Invoice Package XSD schema on 18 December 2025. Taxpayers and service providers need to implement the revised EArsiv.xsd file to stay compliance with e-Archive invoice formatting requirements.

Greece published new API specifications for real-time goods movement tracking via the myDATA platform, adding six REST APIs and enhanced logistics data requirements.

Croatia updated technical specifications for Fiscalization 2.0, tightening digital certificate requirements to ensure secure and accurate taxpayer identity validation.

Malaysia

On 7 December 2025, Malaysia’s Inland Revenue Board updated its E-invoice Guideline (v4.6) and E-invoice Specific Guideline (v4.5). Key changes include:

• Raising the exemption threshold from RM 500,000 to RM 1 million.
• Eliminating the previously scheduled 1 July 2026 implementation phase.
• Confirming that taxpayers with annual turnover up to RM 5 million needed to comply by 1 January 2026.  

These updates eased compliance burdens for smaller businesses while maintaining the overall timeline for larger taxpayers on track.

What E-Invoicing Mandates Mean for European Businesses

If December taught us anything, it is that the pace isn't slowing down. If you're operating across multiple jurisdictions, staying ahead of these changes isn't optional anymore. Here’s a good way to keep on top of it:

• Stay alert: Regulatory changes often occur with little notice. Establish processes to track updates from tax authorities and industry bodies.
• Invest in Technology: Ensure your ERP and invoicing systems can support evolving schemas, validation rules, and API integrations.
• Get your teams talking: Compliance is not just a finance’ problem. Bring IT, procurement, and operations into the conversation early.
• Don't go it alone: Partner with trusted advisors to interpret complex e-invoicing mandates and implement what actually works.

Vertex remains committed to helping businesses navigate the complexities of global e-invoicing. Our solutions enable seamless integration, real-time validation, and automated e-invoicing compliance across jurisdictions. Contact us to learn how we can support your compliance journey.