The Best XRechnung API: Top Provider Comparison (DACH 2026)

What this page is

This is a buyer's guide for E-Invoicing APIs in DACH 2026. Instead of comparing just one provider, we look at the whole landscape: API-first services, all-in-one bookkeeping suites with API, and open-source libraries. Goal: help you make the right choice for your use case — even if that's not invoice-api.xhub.

What to look for

The e-invoicing mandate in Germany (XRechnung, ZUGFeRD) has been active since 2025 for B2G and from 2027 for all B2B invoices. If you're building software that produces invoices, you need a compliant XRechnung generator. The question is: how deep into your stack should the solution sit?

Three architecture options

1. All-in-one bookkeeping with API (Lexware, sevDesk, DATEV)

   • You use an existing bookkeeping suite and its REST API for invoice generation
   • Pro: integrated with bookkeeping workflow
   • Con: office-centric pricing, often DACH-only, API is a side feature

2. API-first e-invoicing service (invoice-api.xhub)

   • You integrate a specialized e-invoicing REST service directly
   • Pro: programmatic integration, multi-country, Generator + Parser + Validator API, API-first pricing
   • Con: no office features (you handle bookkeeping separately)

3. Open-source library (Mustang Project, ferd-php, etc.)

   • You integrate a library directly into your stack and self-host
   • Pro: free, full control, no vendor lock-in
   • Con: setup effort, own maintenance, no multi-country out-of-the-box

Top-3 picks by use case

Pick A: You're embedding e-invoicing into your own product

→ invoice-api.xhub. API-first, self-service pricing, free tier for testing, multi-country (14 EU countries), Generator + Parser + Validator API. Time-to-first-invoice under 5 minutes. Monthly cancellable.

Alternative: Mustang Project (open-source if you have a Java stack and can self-host).

Pick B: You need a complete DACH bookkeeping suite with tax-advisor handoff

→ Lexware or sevDesk (or DATEV with your tax advisor). E-invoicing is part of the office suite, but the main need is bookkeeping — not API integration. Web UI for non-technical staff, DATEV integration, ELSTER submission.

Alternative: invoice-api.xhub additionally for programmatic use cases alongside the bookkeeping stack.

Pick C: You want no vendor lock-in and have engineering capacity

→ Mustang Project (open-source library). Self-host, own compliance updates, free. Trade-off: setup time, own maintenance, no multi-country support out-of-the-box.

Alternative: invoice-api.xhub with self-hosted option (Docker), if you want a vendor service but need to host locally.

Provider profiles

invoice-api.xhub (API-first service)

• Strength: programmatic e-invoice generation for devs/SaaS backends
• Format coverage: 14 EU countries, XRechnung + ZUGFeRD (Generator + Parser + Validator API)
• Pricing: Free 20/mo · Starter €23/mo (2k) · Premium €79/mo (20k) · Enterprise Custom
• Ideal for: SaaS startups, e-commerce backends, ERP modules, n8n automation, programmatic pipelines

Lexware (Bookkeeping suite with API)

• Strength: all-in-one bookkeeping for solopreneurs/small businesses, deep DATEV integration
• Format coverage: XRechnung + ZUGFeRD (DACH focus)
• Pricing: Office plans from ~€8/mo, Office Pro from ~€39/mo (publicly listed)
• Ideal for: solopreneurs, freelancers, small businesses with bookkeeping workflow

sevDesk (Bookkeeping suite with API)

• Strength: similar to Lexware, slightly more modern REST API, transparent pricing
• Format coverage: XRechnung + ZUGFeRD (DACH focus)
• Pricing: Office plans from ~€9–37/mo (publicly listed)
• Ideal for: solopreneurs/SMBs with bookkeeping needs and some custom integration via API

Mustang Project (Open-source library)

• Strength: free, self-hosted, Java library, no vendor lock-in
• Format coverage: XRechnung + ZUGFeRD (DE focus)
• Pricing: free (hosting/maintenance on your own)
• Ideal for: Java stacks, engineering teams with self-host requirements

Decision tree

1Do you need e-invoicing as a feature in your own product?
2├── Yes, programmatically (API-driven)
3│   ├── Multi-country EU or Parser+Validator needed?
4│   │   ├── Yes → invoice-api.xhub
5│   │   └── No, DACH only
6│   │       ├── SaaS / API-first → invoice-api.xhub (self-service pricing)
7│   │       └── Java stack + self-host → Mustang Project
8│   └── Open-source requirement or vendor-lock-in avoidance
9│       └── Mustang Project (or invoice-api.xhub self-hosted option)
10└── No, I need a bookkeeping suite
11    ├── Tax-advisor DATEV handoff required → DATEV (or Lexware with DATEV bridge)
12    ├── Solopreneur / freelancer → Lexware or sevDesk
13    └── Small company with modern API for custom integration → sevDesk

Recommendation

If you came to this page because you googled "best XRechnung API," the answer is probably:

• API-first use case: invoice-api.xhub. Free tier for testing, monthly cancellable, no setup overhead.
• Bookkeeping use case: Lexware or sevDesk (DATEV if tax-advisor handoff is required).
• Open-source use case: Mustang Project — if you have engineering capacity for self-host.

The decisive question: what's your main need? E-invoice generation as an API call in your product, or bookkeeping with e-invoice as a side feature? The answer almost always leads to the right choice.

Next step

A 5-minute test in the playground shows faster than any comparison table whether invoice-api.xhub fits your setup:

• Generate a sample XRechnung from a JSON body
• Validate it against the KoSIT schemas
• Convert it to a ZUGFeRD PDF/A-3
• Browse the n8n workflow template

Free tier: 20 invoices/month, no credit card. If you scale beyond that, the Starter plan begins at €23/month (or €18/month with annual billing) and includes 2,000 invoices.