SoloFlow vs Billit: which Peppol invoicing app in Belgium?

Billit is one of Belgium’s best-known players in invoicing and document management. SoloFlow, for its part, is a mobile-first mini-ERP that arrived on the market in 2026. Since 1 January 2026, B2B e-invoicing via Peppol has been mandatory for every Belgian VAT-registered business: the right tool is no longer a luxury. Here is how SoloFlow and Billit compare, without complacency.

In short: SME/accountant versus freelancer on the move

Billit positions itself as an invoicing and management platform aimed at freelancers as well as SMEs, with a distinctly accounting-oriented focus. SoloFlow targets the freelancer and the very small business that wants to manage everything from a phone: invoices, but also clients, tasks and calendar.

The difference in audience shows in the interface: Billit is richer but also denser, designed to interact with an accountant; SoloFlow is more tightly built around the daily routine of a solo freelancer.

Comparison table

Criterion	SoloFlow	Billit
Starting price	Free (10 docs/month, 50 contacts)	Free (sales invoices only, 1 user)
Paid offer	€9.99/month or €99.99/year	€7.50/month excl. VAT (+€5/extra user)
Real monthly billing	Yes	No (quarterly or annual)
Peppol (send + receive)	Included from the Pro plan	Included at no extra cost
Native mobile app	iOS + Android	iOS + Android
Web app	Yes (app.soloflow.online)	Yes
Built-in CRM	Yes (Contact → Lead → Qualified → Client)	No
Tasks + calendar	Yes (native calendar sync)	No
Offline mode	Yes (real offline-first)	No
Markets / languages	Belgium + France, 7 languages	Belgium (SME-oriented)

What Billit does better

Peppol at no extra cost. At Billit, Peppol e-invoicing is included with no additional billing, including free sending on the Free version. For a freelancer who sends a lot of electronic invoices, having no transaction counter is comfortable. SoloFlow, for its part, includes 50 Peppol transactions per month in its Pro plan (extendable with credit packs), which suits most freelancers but sets a ceiling that Billit doesn’t impose.

Depth for those working with an accountant. Billit is built around the accounting flow: document management, connections to accounting software, processing of incoming invoices. An SME with a dedicated accountant will find a familiar environment there.

Maturity and Belgian roots. Billit is an established player on the Belgian market, with a track record and a client base that SoloFlow, more recent, doesn’t have yet.

What SoloFlow does better

A mini-ERP, not just an invoicing tool. SoloFlow adds to invoicing a CRM (Contact → Lead → Qualified → Client), task management and a calendar synced with yours. You follow the client relationship end to end, without juggling multiple apps. Billit doesn’t cover this sales side.

Mobile-first and offline mode. SoloFlow is designed for the phone first, with a real offline mode: viewing and creating documents without a connection, syncing afterwards. It’s an asset for anyone invoicing on the move, on a job site or at a client’s. Billit offers an app, but its centre of gravity remains desktop use.

Monthly billing and pricing clarity. Billit doesn’t bill monthly: its paid plan is settled quarterly or annually, which is a bigger commitment. SoloFlow offers a real monthly subscription at €9.99 (or €99.99/year), with no long-term commitment.

Belgium + France coverage. SoloFlow works on both sides of the border and comes in 7 languages. In France, it relies on A-Cube, a Plateforme Agréée (PA — French government-accredited platform) registered with the DGFiP. Billit is focused on Belgium.

What does it cost, concretely?

On paper, Billit starts a little cheaper: €7.50/month excl. VAT versus €9.99/month for SoloFlow’s Pro plan. But two nuances matter. First, Billit charges per additional user (+€5/month), whereas SoloFlow is aimed first at the solo freelancer. Second, Billit offers no real monthly billing: you pay quarterly or annually. If you want to try without committing, SoloFlow (free then €9.99/month) is more flexible.

On the Peppol side, Billit sets no transaction ceiling, while SoloFlow includes 50 transactions/month in Pro, extendable with packs of 50 credits at €7.99 (one-time purchase). And until 31 December 2026, SoloFlow offers free e-invoice receiving.

The regulatory context that makes the choice urgent

Whatever the tool, one thing is certain: in 2026, doing nothing is no longer an option in Belgium. Since 1 January 2026, every Belgian VAT-registered business must issue and receive its B2B invoices in a structured format via Peppol (EN 16931 standard). A PDF sent by e-mail no longer fulfils the obligation, and fines can reach €5,000 under Article 70 of the VAT Code. The framework rests on the law of 6 February 2024 and the royal decree of 8 July 2025.

On that ground, both Billit and SoloFlow are operational: both handle the Peppol channel. So the question is not “which one makes me compliant?” — both do — but “which one best fits the way I work day to day?”. If you’re also considering expanding into France, keep in mind that SoloFlow is already present there (via A-Cube, a Plateforme Agréée registered with the DGFiP), where Billit remains focused on Belgium. In France, receiving e-invoices becomes mandatory for all businesses on 1 September 2026, and issuing for small businesses and SMEs on 1 September 2027.

Which tool for which profile?

Choose Billit if: you’re an SME or a freelancer working closely with an accountant, you need advanced document management, you send a high volume of Peppol invoices and want to avoid any counter, and a denser interface doesn’t put you off.

Choose SoloFlow if: you’re a freelancer or a very small business, you want to manage clients, tasks and invoices in one place, you often work on the move (offline mode), you prefer a monthly subscription with no commitment, or you invoice in Belgium and France.

FAQ

Does Billit really include Peppol for free?

Based on information published in July 2026, Billit includes Peppol e-invoicing at no extra cost, with free sending from the Free version (limited to sales invoices and a single user). SoloFlow also includes Peppol in its Pro plan, with an extendable quota of 50 transactions per month.

Does SoloFlow work on a computer like Billit?

Yes. SoloFlow offers native iOS and Android apps as well as a complete web app (app.soloflow.online) accessible from any browser, just like Billit.

Can I pay for SoloFlow monthly?

Yes, SoloFlow offers a real monthly subscription at €9.99 (or €99.99/year). That’s a notable difference from Billit, whose paid plan is settled quarterly or annually.

Which tool for a freelancer just starting out?

If you’re starting solo and want a simple tool covering both invoicing and sales tracking, SoloFlow is the better fit. If you anticipate rapid growth with multiple users and an accountant integrated into your workflow, Billit may better support that scaling up.

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For everything about the Belgian and French timelines, read our 2026 electronic invoicing guide. See also our SoloFlow vs Accountable comparison.

Comparison written by the SoloFlow team based on publicly available information as of July 2026. Spotted an inaccuracy? Let us know: hello@soloflow.online