This only seems to cover invoicing the public sector, I don't see anything about B2B there. The dashboard mentions, "15 countries introduced obligations for issuing B2G eInvoices".
Germany and France, at least, don’t have the issues mentioned here, as our e-invoicing standard is XML based (apparently now also compatible with PEPPOL XML) and doesn’t require an extra network with service fees or certifications.
https://ec.europa.eu/digital-building-blocks/sites/display/D...
Ah now I see that in the fact sheet for every country they write if the legislation also introduces a B2B mandate.
https://ec.europa.eu/digital-building-blocks/sites/display/D...
So currently there are B2B mandates (some in the future) for: Belgium, Germany, France, Italy, Poland(?) and Romania.