EU SaaS solo owner here (about 10 years so far). I gave up on B2C entirely. It's just too much hassle. My accountant starts screaming in horror whenever I mention VAT MOSS. Whenever I looked into the rules, I saw a snake pit with moving snakes.
Additionally, B2C has tight margins, so eating into those hurts a lot.
Whenever I looked at companies like Quaderno, they looked great, but when I actually tried to use them, it turned out that their solutions are far from perfect and often incomplete or simply incorrect (e.g. I would not comply with local laws in my country). This is a common theme: even B2B invoicing, which is far simpler, is not implemented correctly by companies that say they do "invoicing". For example, Stripe invoicing won't do JPK_FA or KSeF in Poland (SAF-T reporting), which pretty much makes it a no-go. Many service providers are also incapable of producing bi-lingual invoices.
I ended up using Braintree (don't make that mistake) and now I'm migrating to Stripe — but for payments only. I have my own subscriptions and invoicing, and I use a local (Polish) company that has an invoicing API to produce JPK_FA/KSeF data.
If I were to even look at B2C, I wouldn't even consider doing anything on my own. I would go with Paddle, carefully considering my margins.
I realize this is not the answer you were looking for but it's a real-life data point.
In my experience tax accountants really are not experienced with MOSS because its quite rare topic. Only chance is to find someone who is open and willing to study it.
Additionally, B2C has tight margins, so eating into those hurts a lot.
Whenever I looked at companies like Quaderno, they looked great, but when I actually tried to use them, it turned out that their solutions are far from perfect and often incomplete or simply incorrect (e.g. I would not comply with local laws in my country). This is a common theme: even B2B invoicing, which is far simpler, is not implemented correctly by companies that say they do "invoicing". For example, Stripe invoicing won't do JPK_FA or KSeF in Poland (SAF-T reporting), which pretty much makes it a no-go. Many service providers are also incapable of producing bi-lingual invoices.
I ended up using Braintree (don't make that mistake) and now I'm migrating to Stripe — but for payments only. I have my own subscriptions and invoicing, and I use a local (Polish) company that has an invoicing API to produce JPK_FA/KSeF data.
If I were to even look at B2C, I wouldn't even consider doing anything on my own. I would go with Paddle, carefully considering my margins.
I realize this is not the answer you were looking for but it's a real-life data point.