Most software vendors choose one of three models: build e-invoicing in-house, use a basic gateway for delivery, or embed a partner API that manages compliance, routing, and operations. The best fit depends on your time-to-market needs, country coverage, and how much ongoing maintenance you want to own.

A gateway typically focuses on sending documents through a network, while you still handle much of the compliance logic, monitoring, and exceptions. An embedded API approach usually goes further by managing regulatory updates, routing complexity, and operational reliability behind the integration.

Building can make sense if you only need one market, have in-house compliance expertise, and are prepared to maintain it as long-term infrastructure. It’s less ideal when you expect frequent regulatory change, multi-country expansion, or want to minimise operational overhead.

Requirements rarely scale linearly across borders. New markets often mean different formats, local rules, network requirements, and exception handling. Many teams find that multi-country readiness becomes the biggest driver behind choosing a partner-based approach.

If you build in-house, your team owns compliance tracking and updates. With a basic gateway, responsibility is often shared or split depending on scope. With an embedded partner API, regulatory change management is typically handled by the partner as part of the service.

Prioritise multi-country coverage, developer-friendly integration and testing, reliable identifier resolution and routing, proven regulatory change handling, and clear SLAs and pricing. Your partner effectively becomes part of your infrastructure, so predictability matters.

Start by mapping your target countries, compliance requirements, and desired customer experience, then compare how each model affects time-to-market and ongoing maintenance. If you want a faster evaluation, a short technical fit discussion can clarify what’s realistic for your roadmap.