Electronic Invoicing | Get Ready for 2026 with OOTI !

The world of architecture has already embraced the digital revolution to design, communicate, and manage projects. Tomorrow, it’s your invoicing process that will shift into the 100% digital era. In September 2026, electronic invoicing will become mandatory for most French companies. No more PDFs sent by email—structured formats and automated exchanges will take over. But contrary to popular belief, you don’t need to wait until 2026 to act. Agencies that prepare now will gain a decisive competitive edge. Here’s your roadmap for a successful transition.

2026 | The deadline!

In September 2026, a major transformation awaits all architecture firms, design offices, and indeed all French companies: mandatory electronic invoicing (the famous “dematerialization of invoices”). Initially scheduled for July 2024, the reform will now roll out according to a revised timeline.

Key dates to remember:

• From September 1, 2026: all companies must be able to receive electronic invoices.
• Large companies and mid-caps must also issue them at this date.
• SMEs have until September 2027 for mandatory issuance.

This reform pursues three strategic goals:

• Combat VAT fraud (which costs the French state billions annually),
• Modernize business exchanges,
• Simplify reporting obligations.

For your agency, this means the end of PDF invoices sent by email in B2B. You’ll need to adopt new standardized formats: Factur-X (most recommended), UBL, or CII, and transmit them via a certified Partner Dematerialization Platform (PDP) or the Public Invoicing Portal (Chorus Pro).

The challenge goes beyond compliance: in Germany, where Factur-X is already deployed, companies have reported a 60% reduction in invoice processing time.

Diagnosis | 4 steps to assess your readiness

Before choosing an electronic invoicing solution, you must carry out a full audit of your current situation. Vincent Giraud, chartered accountant and e-invoicing specialist at PKF Arsilon, emphasizes that “the diagnostic alone can take three weeks to a month in an SME or mid-cap,” but major hurdles, such as an ERP migration, can significantly extend timelines.

Step 1: Audit your invoicing processes.
Analyze your incoming and outgoing flows: B2B invoicing, relationships with public clients, subcontractors. Identify all stakeholders in your invoicing cycle: who issues, approves, triggers payments.

Step 2: Check data quality.
Verify the reliability of your client database: VAT numbers provided, no duplicates, complete records. A missing VAT number will lead to automatic rejection of your invoice by the PDP.

Step 3: Map your IT environment.
List all tools connected to invoicing: management software, ERP, CRM, accounting tools. Check their compatibility with the mandatory new formats.

Step 4: Identify non-compliance points.
List the necessary adjustments: software updates, process changes, team training.

We recommend launching this diagnostic now and finalizing your action plan by late 2025/early 2026 for a smooth implementation.

How to choose the right solution?

Once your diagnostic is complete, you must choose between two approaches:

• Public Invoicing Portal (Chorus Pro)
• Private Partner Dematerialization Platform (PDP)

Chorus Pro centralizes transmission to the tax authorities and ensures regulatory compliance. This official solution manages exchanges with clients via PDP interconnections and offers secure archiving.

Certified PDPs provide greater flexibility and automation. They authenticate invoice receipt/transmission for clients and automatically extract regulatory data for the tax authorities. PDP use requires an explicit opt-in mandate—no platform can impose itself.

Four decisive criteria for your choice:

• Compliance: prioritize solutions that natively generate Factur-X, a hybrid format combining a human-readable PDF and structured XML file, compliant with European standard EN16931.
• Integration: check compatibility with your existing tools to avoid duplicate entries and workflow breaks.
• Automation: look for automatic issuing, sending, tracking, and reminders with clear dashboards.
• Support: training, responsive assistance, and regulatory updates included are a big plus!

OOTI meets all these criteria by natively integrating Factur-X, Chorus Pro/PDP connectivity, advanced automation features, and full support for a seamless transition. Remember: processing a paper invoice costs 2 to 3 times more than an electronic one.

Your roadmap to September 2026 | Don’t react, anticipate

• Starting now: Train on regulatory obligations and launch your full diagnostic (3–4 weeks). Identify your routing needs and map your flows.
• By late 2025/early 2026: Finalize your solution choice, configure invoice templates in Factur-X format, and train your teams on new processes.
• Before summer 2026: Issue your first electronic invoices in real conditions, correct potential issues, and gradually scale up.
• September 2026: Complete transition with a native Factur-X solution connected to your chosen PDP.

Want to learn more? We'll soon upload a dedicated white paper with a checklist to make sure you don’t miss a step.

With OOTI, electronic invoicing becomes your advantage: built-in compliance for 2026, fully automated processes, and predictable cash flow weeks in advance. While competitors worry about looming deadlines, you free your teams from repetitive tasks and focus on what matters most: your architecture projects. No more manual entry, missed reminders, or administrative stress. Your invoicing becomes invisible, reliable, and responsive.

Start anticipating now: experience the simplicity of OOTI. Request your personalized demo.