Commercial System - Offers, Billing and E-Invoicing

From Offer to Invoice, Dunning and Compliant E-Invoices

2026 Customer Project

Project Description

This project implements an end-to-end commercial stack: database-backed offers and contracts with positions and legal documents, Faktura workspace for invoices, payments, credit notes and dunning, in-house XRechnung/ZUGFeRD e-invoicing (EN 16931), pre-commit and after-the-fact validation, document number series, KPI dashboards, and Outlook-style commercial mail compose. Commercial PDFs are WORM-archived via the document archive on print and lock.

Key Features

Offers & Contracts

Positions, legal docs, Pflichtenheft and acceptance workflows

Billing & Invoices

Issue, lock, payments, credit notes and batch billing runs

Dunning

Configurable dunning rules, fees, Mahnlauf and dunning PDFs

E-Invoicing

XRechnung CII XML and ZUGFeRD PDF embedding (EN 16931)

E-Invoice Validation

Validation workspace and Sanctum validate API for XML/PDF

Commercial Mail Compose

Outlook-style compose modal for offers, contracts, invoices and dunnings

Technology Stack

Backend Framework

Laravel 11
PHP 8.2+
MySQL

Frontend

Livewire
Alpine.js
Bootstrap

Architecture

SOLID Principles
Service Layer
Queued Jobs

E-Invoice Standards

XRechnung
ZUGFeRD
EN 16931

Workflow

  1. Offer: Create offer with positions and send via mail compose
  2. Contract: Convert accepted offer, archive Pflichtenheft on accept
  3. Invoice: Issue and lock invoices from bookings; archive PDF
  4. E-Invoice: Embed ZUGFeRD or export XRechnung XML
  5. Validate: Run validator workspace before or after commit
  6. Dunning: Execute Mahnlauf with fees and dunning PDFs
  7. Archive: Commercial PDFs land in the WORM document archive