Electronic invoice creation/viewing/validation

[Artim96]

I was reminded today that by 2025 we must be able to at least receive electronic invoices that comply with the European guideline 2014/55/EU. In practical terms, the format "XRechnung" (pure XML format) must be supported, other formats like "ZUGFeRD" (v2.2 of this is what's known as "Factur-X" in France) are optional. Additionally, companies we have contact with may require us to send them such electronic invoices, although we hardly have to write that many invoices.

Anybody knows a software that runs at least on Linux that can view, validate and create/export invoices that are at least compatible with XRechnung? ZUGFeRD seems to be not that uncommon, yet politicians decided to make the inferior XRechnung format mandatory that pretty much nobody was using. A self-hostable web service would also be acceptable, although after setting up my fair share of various web services and getting into rages because of very lacking descriptions for that I'd prefer not having to. Also, due to the foreseeably low invoice volume - when we receive 20–30 invoices and have to create 5–10 invoices per year, that's a lot, and I doubt that they will all be switched to electronic invoices any time soon - we'd prefer not to have to pay 8 € per month as a voluntary based non-profit.

And it would be a nice feature if it was possible to create entries in GNUCash from an invoice, but it's not a necessity.