A closer example might be the MPAA (US film rating group). It's a voluntary certification, but it's become a de facto requirement such that the small, opaque, non-government group shapes the level of violence (high) and nudity (low) in all TV and films.
Right or wrong I have always associated refusal to use traditional banking a more hard-line Muslim belief.
Edit:
For most Sharia fintech startups, MUI certificates are not only commercially advantageous but legally required by the Financial Services Authority of Indonesia (OJK), the state financial regulator. Other areas of the Sharia digital economy, like halal e-commerce and umrah sites, travel-booking platforms for Islamic pilgrimages, do not require this certificate.
So yes for fintech, maybe for ecommerce in general?
https://www.ojk.go.id/en/berita-dan-kegiatan/siaran-pers/Pag...
Participating in the Indonesian sharia finance economy would be more akin to something like organic certification on produce. Most farms are not organic but if you want to label your products as such then you have to undergo a certification process with an agency like the USDA. In this case to be certified Halal you have to gain the MUI certificate which is recognized by the OJK Financial Services Authority of Indonesian. However, an Indonesian person is likely better person to clarify this more precisely.
>>Well obviously. If you want to build a halal certified banking product it has to be implement syariah principles, thats the point.