Invoice-api.xhub Blog

Insights, tutorials, and news about e-invoicing, API development, and the German compliance landscape.

Your Own Fields on an E-Invoice — Without Losing Conformance
FeaturedGuide

Your Own Fields on an E-Invoice — Without Losing Conformance

Vessel name, job number, machine serial: data EN 16931 doesn't know but your customer needs. Why a hybrid e-invoice has two layers — and where the boundary actually runs.

Patrick JerominekSeptember 7, 20268 min
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From PDF Invoice to E-Invoice: What Our First Customer Pipeline Taught Us
Integration

From PDF Invoice to E-Invoice: What Our First Customer Pipeline Taught Us

A facility services company writes its invoices in Word and Excel and must send e-invoices from 2027. How we built a pipeline behind that with n8n and the invoice-api — without a language model, with seven mapping errors that only the real API call revealed, and three findings in our own API.

Patrick JerominekAug 299 min
E-Invoicing Mandate 2025: n8n Automation for Small Businesses
Guide

E-Invoicing Mandate 2025: n8n Automation for Small Businesses

Germany's e-invoicing mandate affects every business. How SMBs automate invoice creation for free with n8n and the xhub.io API — incl. ROI numbers.

Patrick JerominekJun 810 min
Automatically Validate and Archive E-Invoices with n8n
Tutorial

Automatically Validate and Archive E-Invoices with n8n

Fully automated n8n workflow: receive e-invoices via email, auto-detect the format, validate and archive compliantly — with Slack error alerts.

Patrick JerominekMay 1115 min
Customize invoice templates via API: BlockTemplate tutorial
Tutorial

Customize invoice templates via API: BlockTemplate tutorial

How to generate PDF invoices with logo, brand colors and dynamic VAT rows using JSON only. Incl. EN 16931 compliance and ZUGFeRD pitfalls.

Patrick JerominekApr 148 min
Create XRechnung with n8n — Step-by-Step Tutorial
Tutorial

Create XRechnung with n8n — Step-by-Step Tutorial

Learn how to automatically create XRechnung invoices with n8n and Invoice-api.xhub. From Google Sheets to validated XML — completely without coding.

Patrick JerominekApr 1112 min
Our Biggest Customer Is Ourselves: Dogfooding at xhub.io
Product

Our Biggest Customer Is Ourselves: Dogfooding at xhub.io

invoice.xhub.io runs on the same API we offer developers. A dogfooding story about shared libraries, real validation and our own pitfalls.

Patrick JerominekFeb 128 min
E-Invoicing Mandate 2025: Complete Guide for Developers
Compliance

E-Invoicing Mandate 2025: Complete Guide for Developers

E-invoicing becomes mandatory for B2B in 2025. Technical guide with code examples for XRechnung, ZUGFeRD, and Peppol. Implementation checklist included.

Patrick JerominekJan 2015 min
Automatically Validate E-Invoices with n8n
Integration

Automatically Validate E-Invoices with n8n

Automated invoice validation with n8n and Invoice-api.xhub: schema checks, error diagnosis and escalation — completely without code.

Patrick JerominekJan 1510 min

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