Still managing quotes, invoices and payments across multiple tools?
I built a complete financial system that runs on your own domain.
Not a SaaS.
No subscription.
No critical dependencies.
The system runs on your own hosting.
Quotes → online signature → invoicing → payment confirmation → revenue journal.
Everything is semi-automated.
Quote / contract
Simple interface:
- your fixed company details
- client information
- service lines
- currency / VAT
- your fixed banking details
The PDF is generated directly in the browser and sent to the client by email.
No data is sent to the server before validation.
Once the quote is sent:
- a secure link is sent to the client
- the client can view and sign the quote online
- the quote is archived
- you receive a confirmation email
The quote then becomes a signed contract.
Invoicing
The system includes a smart client lookup.
You only need to enter a single piece of information:
- SIRET / SIREN
- client name
and the system automatically retrieves:
- the client’s details
- their existing quotes (a list is suggested in the quote field)
The most recent quote is automatically suggested.
You simply select the correct quote from the list.
The system retrieves:
- service lines
- amounts
- client information
If no quote exists, the invoice can be generated directly with a free service description.
Once validated, the system immediately generates:
- the invoice
- the stamped invoice (pre-generated)
The invoice is sent to the client and archived.
The stamped version is stored while waiting for payment.
Payment confirmation
The interface lists all pending invoices.
One click is enough to:
- mark the invoice as paid
- send the stamped invoice
- add the entry to the revenue journal
The system also allows:
- monthly invoice export (ZIP)
- monthly revenue export (CSV)
- annual revenue journal export
All data is stored in simple files.
No database.
This system is designed to be:
- autonomous
- installable on any PHP hosting
- bilingual FR / EN
- fully documented
The data stays with the client.
https://palks-studio.com/en/invoicing-without-saas
This is the type of systems I design at Palks Studio:
simple tools that automate complete business processes.
If you want to install this system on your own infrastructure:
If you're interested in how it works under the hood:
Here’s a technical breakdown of the system architecture.
Overview
Billing System is a suite of three interconnected billing tools accessible from a unified interface. It covers the full lifecycle of a service engagement: from quote generation to invoice settlement, including electronic signature and structured archiving.
The system is designed to be deployed directly on the client's server, on a standard Apache hosting environment with PHP 8.x and Composer. It requires no database, no third-party service, and no subscription.
Features
- Client-side quote PDF generation (jsPDF)
- Server-side invoice PDF generation (Dompdf)
- Automatic pre-generation of the paid invoice at billing time
- Electronic quote signing by the client (touch/mouse canvas)
- Client auto-fill from archives (SIREN, SIRET, VAT, email, name)
- Structured archiving by client and period
- Secure sequential numbering (file lock)
- Monthly export of invoices (ZIP)
- Monthly export of revenue records (CSV)
- Yearly export of the revenue journal (CSV)
- Automatic email notifications at each stage (quote, invoice, settlement)
- Cross-module navigation bar
- Bilingual FR/EN interface with real-time language switch
- Dark mode / light mode with persistence
- No database
- No SaaS dependency
- Basic security: secure sessions, tokens, brute-force protection
Project Structure
billing-system/
│
├── public/
│ │ └── assets/
│ │ ├── logo* → Company logo if provided
│ │ ├── signature.png → User signature used on quotes and invoices (PNG format)
│ │ └── favicon* → Optional favicon displayed in the browser tab
│ │
│ ├── Endpoint a → Quote generation endpoint
│ ├── Endpoint b → Invoice generation endpoint
│ ├── Endpoint c → Direct invoice generation endpoint
│ ├── Endpoint d → Paid invoice generation endpoint
│ │
│ ├── Interface a → Quote generation interface
│ ├── Interface b → Direct invoice generation interface
│ ├── Interface c → Payment tracking interface
│ ├── sign.php → Signature interface
│ ├── export a → Archived invoices ZIP export
│ ├── export b → Revenue journal CSV export
│ │
│ ├── search.php → Client search and auto-fill
│ ├── serve.php → Secure PDF access via token
│ └── save.php → Quote save and archiving
│
├── vendor/ → Libraries used by the document generation engine
├── templates/ → HTML templates used for document rendering
│
├── app.php → Central configuration for issuer and bank details
├── mailer.php → Internal email sending script with attachments
├── core.php → Main engine: generation logic, calculations and archiving
├── LICENSE.md → Project license
│
├── contracts/ → Signed and unsigned quote archiving
├── counters/ → Numbering counters (quotes and invoices)
├── logs/ → System logs (optional)
├── data/ → Operational data
│
└── docs/
├── USER_GUIDE.md → User guide
├── OVERVIEW.md → Project overview and general system description
└── README.md → Installation and usage documentation (client version)
If you want to explore the technical implementation, you can find it here:
https://github.com/Palks-Studio/billing-system
Top comments (2)
Super insightful build—highlighting how freelancers need more than just invoicing tools but a complete financial system is spot on. This feels like a real step toward financial independence through tech 🚀
Appreciate it.
Most issues I see aren’t about invoices themselves, but fragmented workflows.
The goal is to replace that with a single, structured system that runs on its own.