Dutch-born SINCERIUS expands into Belgium, combining its proven data-driven due diligence model, Big Four seniority and entrepreneurial culture with deep local dealmaking expertise under new partner, Koen Vermoere.
Financial due diligence boutique SINCERIUS opens an office in Antwerp on 14 September 2026. Koen Vermoere (partner) and Vince Delcroix (director) – Big Four alumni specialising in financial due diligence – will lead the practice, backed by the Dutch organisation's 50 professionals. With that, SINCERIUS brings a combination of seniority, personal involvement and a data-driven due diligence approach to private equity, entrepreneurs and corporates in the Belgian mid-market.
Photo (from left to right): Joost Siemensma, Koen Vermoere, Vince Delcroix. By: Sarah Wijzenbeek
The entrepreneurs behind the Belgian practice
SINCERIUS is convinced that local presence, personal approach and cultural understanding matter. That is why Koen is starting up the Belgian practice after close to 25 years at PwC, including a stretch in Australia. Back in Belgium, he was instrumental in growing the transaction services team, led numerous financial due diligence engagements for key clients, worked on restructuring services during the financial crisis, and spent years leading HR, recruitment, as well as learning and development. He will now use that experience to build the local team, while his own focus remains buy-side and sell-side financial due diligence for private equity and corporate clients.
"What attracted me was the chance to build a genuinely Belgian, senior-led financial due diligence practice from the ground up," Koen says.
"You combine the agility and personal involvement of a boutique with the scale, specialist depth and technology of a proven platform. I am excited to build the team, stay close to the work and shape the business as part of the growth story of SINCERIUS and PIA Group."
Koen will be joined by Vince as a director at SINCERIUS. Combined, the two Big Four alumni have completed hundreds of due diligence projects across a wide range of sectors and deal sizes. They also worked closely on several complex sell-side financial due diligence assignments in recent years, giving the practice an established working rhythm from day one.
The team will grow from there with specialists in financial due diligence and data. "We are looking for people with an interest in finance as well as data science," Koen says. "The ambition is to build substantial local capability while staying fully integrated with the wider SINCERIUS team."
Entering Belgium with scale from day one
Koen sees Belgium as the logical next step for SINCERIUS. The mid-market there is active and relationship-driven, with local and international private equity firms, as well as a large base of founder- and family-owned businesses.
Koen also notes a clear shift in the mid-market toward specialised financial due diligence providers. "PE sponsors and corporates increasingly value senior hands-on involvement, speed, consistency and a pragmatic, efficient way of working," he says. "Building that relationship with your client usually happens on the ground. If you provide a good service, clients come back to you for subsequent deals and add-ons."
From day one, the Belgian practice is backed by the 50-person SINCERIUS team, a 16-year track record, industry credentials, technology and support from PIA Group. "That gives us scale without the capacity constraints of a standalone boutique," Koen says. Existing Dutch private equity and corporate relationships add to that, giving the practice a head start in cross-border deal flow.
The data-driven approach crosses the border
SINCERIUS's data-driven approach dates back to the boutique's founding. In 2010, after ten years at Big Four firms, Joost Siemensma set out to build a boutique firm with a different approach to financial due diligence. "During that decade, I sometimes missed serving as the right-hand man to entrepreneurs. I wanted to do things differently, to deliver added value instead of just billing hours," he looks back.
SINCERIUS has since grown to a team of 50 people versed in fields from finance to data science, advising on more than 150 transactions a year and named Best Transaction Services Firm Mid-Market at the M&A Awards hosted by the M&A Community Netherlands (mena.nl) for five consecutive years. The foundation for that position was laid early on.
"We were the first boutique firm to hire developers and data scientists," says Joost. "This has given us a significant head-start in automation, machine learning and currently AI."
For Joost, the lesson from being a front-runner is that technology leadership is temporary unless innovation continues: "We led the way in extracting large batches of financial data, then in dashboarding, and now AI is changing the game again," he says. Business Insight brings that innovation and the firm's data capability together in one platform. "With Business Insight, we can quickly extract data from financial and operational systems and process that into overviews or dashboards," elaborates Joost. "Within a couple of days, we have insight into a company, updated daily using our platform."
He points out that this is especially important for PE investors. "Historically, financial due diligence reports were a photo of the company at a specific point in time. We treat them like a film instead. Business Insight keeps updating during the deal and after closing, so our PE clients can use that same view to monitor their portfolio and report on KPIs. We also see that they use it to prepare for an exit, so they are ready whenever a buyer approaches."
As SINCERIUS enters Belgium, it looks forward to a new chapter of growth and innovation.
