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Belgium · Agentic SaaS development

SaaS Development for Belgium, from Peppol Invoices to Tenants

Since 1 January 2026, a Belgian SaaS company liable to VAT has had to send its Belgian business customers structured electronic invoices over the Peppol network, and a PDF sent by e-mail no longer counts. Invoicing is now part of the product, alongside the 21% standard VAT rate, newer account-to-account checkout options and EU switching terms.

Curiosive builds SaaS products from Ankara, Türkiye, with AI coding agents producing the volume under senior engineer review. Engineers design the multi-tenant data model, tenant isolation, plan and entitlement logic and billing webhooks; agents produce the CRUD screens, admin views, migrations and test suites around them. Ankara is one hour ahead of Brussels in summer and two in winter, leaving 7 to 8 office hours a day in common.

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Peppol e-invoicing for SaaS companies billing in Belgium

The B2B mandate covers invoices between Belgian enterprises liable to VAT. Invoices to private individuals are excluded, and e-invoicing to public authorities has been compulsory for contracts published after 1 March 2024. FPS Finance confirmed on 27 March 2026 that its three-month penalty tolerance would not be extended, so it has been over since 1 April 2026 and escalating penalties of up to €5,000 now apply. Customers matter too: the Commission's eInvoicing country page lists foreign taxpayers with a Belgian VAT number but no permanent establishment as excluded recipients, so billing must know which kind of customer it is invoicing. On 18 July 2026 the Council of Ministers also approved a preliminary draft law for near-real-time e-reporting of invoice data, envisaged from 1 January 2028; as reported on 27 July 2026 it still had several steps to pass. Each customer's invoicing route is stored as data, so a rule change is a data update.

VAT on SaaS subscriptions sold from and to Belgium

Belgium's standard VAT rate is 21%, with reduced rates of 6% and 12% and a 12% parking rate, according to the Your Europe table last checked on 13 July 2026. A Belgian vendor selling to a business in another EU country usually charges no Belgian VAT: the customer pays VAT at its own country's rate under the reverse charge, although there are several important exceptions. Electronic services sold to consumers are taxed in the customer's country, although below a EUR 10 000 threshold they may be taxed where the seller is established. The One Stop Shop lets a seller declare those cross-border supplies through a single EU country. In the product, tax treatment is decided per customer from country and VAT number, stored with each invoice and tested as its own scenario. An accountant should confirm the treatment for your own sales.

Wero checkout and strong customer authentication in Belgium

The European Payments Initiative launched Wero for e-commerce payments in Belgium in a release dated 3 March 2026, starting with ING, KBC and BNP Paribas Fortis. Belfius was announced to follow, while Argenta, Crelan, Bunq and Revolut are to be integrated progressively in the second half of 2026. Mollie and Stripe are among the supporting partners. Whether Wero suits renewals as well as first payments is a question for your payment provider. Since 14 September 2019 the PSD2 standards on strong customer authentication have let providers skip it for remote payments of up to EUR 30 only while the payer stays within a cumulative EUR 100 or five consecutive transactions, so challenged and failed payments are ordinary events. Webhook handlers are idempotent, so the same event arriving twice changes nothing. PicKey (pickey.ai) was built with subscription billing on Stripe.

Accessibility and EU Data Act duties for SaaS sold in Belgium

Belgium transposed the European Accessibility Act for consumer banking and e-commerce services through the Law of 5 November 2023, with the requirements in Annex 1 of Book VIII of the Code of Economic Law, applying since 28 June 2025. The Economic Inspection of the FPS Economy enforces it, with sanctions of up to €200,000 or 6% of annual turnover for the most serious breaches, while micro-enterprises get an extra five years. For consumer products in those areas, accessible forms, focus states and contrast belong in the component library from the start. The EU Data Act has applied since 12 September 2025 and places SaaS among data processing services. Until 12 January 2027 switching charges are capped at costs directly linked to the switch; from that date none are allowed. The Digital Omnibus proposal to amend the Data Act was still tabled on 20 September 2026, so the current text applies.

Tenant isolation and how agents build a SaaS product

Tenant separation is decided in the data model, before any screen exists. An engineer designs how each customer's rows are scoped in PostgreSQL, how plans map to entitlements and which paths need a permission check, then reads every change that touches them. Agents produce the volume: CRUD screens, admin views, Drizzle ORM migrations and test suites that try to read across tenants and must fail. Their changes arrive already type-checked, linted and tested, and none merges without senior review. Reveal Software (reveal.software) runs on Hono, Drizzle ORM and PostgreSQL, and Inspire Film (inspire.film) handles per-title entitlement for a virtual cinema. Work runs as AI-accelerated development, starting from $2,000 per month, with scope agreed in writing.

Proof

Published project examples

Reveal Software

Reveal Software

Release Coach AI

Release Coach AI

Inspire Film

Inspire Film

Poppin

Poppin

Zing Coach

Zing Coach

ChurchBee

ChurchBee

AI-accelerated development
from$2,000
per month

Senior engineers building your product with AI coding agents: web, mobile, SaaS or browser extension, reviewed before anything ships.

  • Web, mobile, SaaS and browser extensions
  • AI-assisted delivery under senior engineer review
  • Scope and capacity agreed in writing, renews monthly

AI-accelerated development, billed monthly. We confirm scope, capacity and start date in writing before checkout.

Questions

The things people ask before starting.

Does my Belgian SaaS have to send Peppol e-invoices?

Yes, if it is a Belgian enterprise liable to VAT invoicing other Belgian enterprises liable to VAT. Since 1 January 2026 those invoices must be structured and exchanged over Peppol. Invoices to private individuals are excluded, and with the tolerance period over since 1 April 2026, penalties of up to €5,000 can apply.

What VAT rates does Belgium use, and how do they affect SaaS billing?

The standard rate is 21%, with reduced rates of 6% and 12%. Which treatment a sale gets depends on the customer: business buyers in other EU countries usually fall under the reverse charge, while consumer sales of electronic services are generally taxed in the customer's country. Billing has to record the treatment on every invoice.

Does the EU Data Act let SaaS customers in Belgium switch providers?

Yes. For data processing services in the SaaS model it requires a written contract, a notice period of at most two months and a transitional period of at most 30 calendar days. Some duties do not apply to a service mostly custom-built for one customer, and the provider must say which before the contract is concluded.

Is Wero available for online payments in Belgium?

Yes, since its e-commerce launch there in a release dated 3 March 2026, starting with ING, KBC and BNP Paribas Fortis. More banks are to join progressively in the second half of 2026. Mollie and Stripe are supporting partners, so availability in your checkout depends on your payment provider.

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How it starts

What happens after you write to us.

  1. 01

    You describe the product

    One paragraph on what you are building, roughly when you need it, and who it is for. No brief, no form with fifteen fields.

  2. 02

    You get a reply within a day

    From the engineer who would do the work, not a sales team. If we are not the right fit we say so, and where possible we point you somewhere better.

  3. 03

    You get a scoped plan

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No long contract to begin, no lock-in to our tooling, and the code is yours from the first commit.

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Ankara / Türkiye · Working across European and US time zones