DDD Invoices, a Ljubljana-based startup building API-driven infrastructure for tax-compliant e-invoicing, has closed a €1.31 million seed round as governments increase real-time invoice reporting requirements.

The round was backed by Fil Rouge Capital, which the company described as its first institutional investor, alongside 500 Global and angel investors and advisors from the e-invoicing, ERP, and Peppol ecosystem.

DDD Invoices develops a single integration layer that connects ERPs, accounting systems, and SaaS platforms to tax portals, Peppol networks, and real-time reporting systems across jurisdictions. The startup says the new funding will be used to expand country coverage, speed up and simplify integration deployments, and hire across product, engineering, and go-to-market.

The raise points to growing investor interest in the infrastructure needed to help software platforms and businesses navigate increasingly fragmented global e-invoicing and compliance rules.