The verdict in three sentences
Receiving e-invoices has been mandatory for all French companies since 1 September 2026, and issuing them becomes mandatory for SMEs on 1 September 2027, while Belgium, Germany and Poland run their own deadlines. A B2B e-commerce site must therefore produce structured invoices (Factur-X, UBL or CII), send them through an accredited platform and collect new customer data such as company registration numbers. The adaptation budget is around EUR 5,000 to 15,000 excl. VAT, plus EUR 0.10 to 0.50 per invoice, and it is best committed before the end of 2026.
The calendar B2B sellers must follow
The French reform is part of a European shift. A site selling to businesses in several countries must track several deadlines.
| Country | Mandatory receipt | Mandatory issuing | Format or network |
|---|---|---|---|
| France | 1 September 2026, all companies | Sept. 2026 large and mid-caps, Sept. 2027 SMEs | Factur-X, UBL, CII via accredited platform |
| Belgium | 1 January 2026 | 1 January 2026 | Peppol BIS |
| Germany | 1 January 2025 | 2027 (revenue > EUR 800,000), 2028 for all | XRechnung, ZUGFeRD |
| Poland | February 2026 | February to April 2026 by size | KSeF |
| Spain | Phased 2026-2027 calendar | By size, after decree | Verifactu, Facturae |
| European Union (ViDA) | Intra-EU transactions | 1 July 2030 | EN 16931 standard |
For a French SME, the useful window is the year between the receipt mandate (already in force) and the issuing mandate. In practice, many large accounts already demand structured invoices in 2026.
What the e-commerce site must change
The invoice is no longer a PDF sent by email. It becomes a data flow sent to the accredited platform, which routes it to the customer and passes tax data to the authorities.
| Site component | Required change | Indicative budget excl. VAT |
|---|---|---|
| Customer account form | Collect and validate company ID, e-invoicing address | EUR 800 to 2,000 |
| Invoice generation | Switch to Factur-X or UBL with new mandatory fields | EUR 2,000 to 5,000 |
| Accredited platform connector | Sending API, status feedback (submitted, rejected, paid) | EUR 2,000 to 6,000 |
| Credit notes and refunds | Structured credit notes linked to the original invoice | EUR 500 to 1,500 |
| E-reporting | Transmit B2C and international sales | EUR 800 to 2,500 |
| QA and documentation | Tests with 3 to 5 pilot customers | EUR 1,000 to 2,000 |
The total covers the EUR 5,000 to 15,000 range for a custom site or a mainstream e-commerce CMS. SaaS platforms (Shopify, Shopware) offer connector apps, but customer data still has to be adapted.
Choosing your accredited platform
Accredited platform pricing varies widely with volume. As a 2026 order of magnitude:
| Annual invoice volume | Cost per invoice | Monthly subscription | Estimated annual cost |
|---|---|---|---|
| Under 1,000 | EUR 0.40 to 0.50 | EUR 0 to 30 | EUR 400 to 860 |
| 1,000 to 10,000 | EUR 0.20 to 0.35 | EUR 30 to 100 | EUR 560 to 4,700 |
| 10,000 to 50,000 | EUR 0.12 to 0.20 | EUR 100 to 300 | EUR 2,400 to 13,600 |
| Over 50,000 | EUR 0.10 or flat fee | On quote | Negotiated |
The deciding criteria are API quality, lifecycle status handling, compatibility with your ERP or accounting software, and support response time. Non-compliance in France exposes you to a fine in the order of EUR 15 per non-compliant invoice, capped at EUR 15,000 per year under current rules.
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Mini case study
Nathalie, CFO of a Lyon SME selling industrial supplies online to 1,800 business customers, issues 14,000 invoices per year. She has her site adapted for EUR 11,000 excl. VAT: company ID collection, Factur-X generation, API connector and e-reporting. The accredited platform costs her EUR 0.18 per invoice plus EUR 120 per month, or EUR 3,960 per year. In return, she eliminates printing and mailing 3,500 invoices (EUR 1.20 each, or EUR 4,200) and cuts her average payment time by 6 days thanks to automatic statuses. On EUR 900,000 of receivables, that frees roughly EUR 15,000 of cash. The project pays back in under two years, and the SME is ready a year before the issuing deadline.
FAQ
Should an SME act in 2026 if issuing is only mandatory in 2027?
Yes, because receipt has been mandatory since September 2026 and large customers already demand structured invoices. A 3 to 4 month project started in late 2026 leaves a comfortable margin.
Is a plain PDF still valid?
Not between VAT-registered French businesses after the issuing deadline. Factur-X combines a readable PDF with a structured XML file, which eases the transition.
Are consumer sales covered?
They fall under e-reporting: aggregated transaction data is sent, with no e-invoice to the customer. The connector costs EUR 800 to 2,500 excl. VAT.
What if the customer has no French company ID?
This applies to foreign customers and some associations. The site must handle these exceptions, which go through international e-reporting, and that takes 1 to 2 development days.
How long does the adaptation take?
Plan for 6 to 12 weeks for a B2B e-commerce site, including 2 weeks of tests with pilot customers before full rollout.
Let's scope your project. Tell us your e-commerce platform, annual invoice volume and accounting software: we will price the adaptation and the accredited platform connector. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
