Yep. Invoice software is country specific. One can sell invoicing software to several countries, it just can not be the same software. And no, you can't just abstract the differences, because the invoices focus changes widely.
At least we are in a situation where the seller is almost only subject to the laws of the seller's country. There are some exceptions, but one can mostly deal with those (the EU has plenty, the good news is that if the seller is not also on the EU, most do not apply).
Also, I haven't seen a country accounting system that made accounting papers inherently expensive. Some make refunds very expensive, but not the papers. It's more a matter of badly designed software and processes.
At least we are in a situation where the seller is almost only subject to the laws of the seller's country. There are some exceptions, but one can mostly deal with those (the EU has plenty, the good news is that if the seller is not also on the EU, most do not apply).
Also, I haven't seen a country accounting system that made accounting papers inherently expensive. Some make refunds very expensive, but not the papers. It's more a matter of badly designed software and processes.