Hey HN,

I'm a solo founder running a service business through an Estonian e-Residency company (OÜ). Every time I invoiced a client in another EU country, I had to manually check if reverse charge applies, validate their VAT number on VIES, and figure out the correct tax treatment. I got tired of Googling the same rules over and over, so I built the tool I wanted.

Invoxo automatically determines the correct VAT treatment for each invoice based on seller/buyer countries, VAT registration status, and buyer type. It covers:

- VIES VAT number validation (real-time, with proof retention) - Reverse charge auto-detection for EU B2B - OSS handling for B2C digital services - Immutable tax records locked at issuance

The tax engine routes every invoice through a regime-specific decision system — no hardcoded rules in the UI layer. Tax payloads are versioned and hashed for audit.

It's built for service businesses only — no goods, no customs, no margin schemes. That constraint keeps the tax logic correct rather than approximately correct.

Stack: Laravel, TaxRegimeRouter that isolates each regime's decision logic, treatments, and payload schemas.

14-day free trial, plans from €19/month.

https://invoxo.eu

Happy to answer questions about EU VAT edge cases or the architecture.