FOSSInvoice
FOSSInvoice is a free, open sourced, desktop application desgined to be used by any company that want a easy and lightway Invoice system. It's a fully local application, with no need to create accounts, external services or even Internet access.
What It Does
Create and manage invoices for multiple business identities ("companies") in one place, generate clean PDF documents with your branding, and keep everything stored in a portable database file you fully own.
Core Product Principles
| Principle | What it Means |
|---|---|
| Focused Scope | Invoicing essentials first. Avoid bloat. |
| Local‑First | All data lives on your computer. No forced cloud. |
| Multi‑Company | Manage multiple companies. Switch easily between them. |
| Portable Data | A single database file you can copy, move, version, or back up. |
Key Features (Early Stage)
- Manage multiple companies (name, tax ID, address, contact details, logo)
- Maintain a list of clients per company
- Draft invoices with line items (quantity, unit price, automatic totals)
- Single tax rate + optional absolute discount per invoice (more flexible tax/discount logic coming)
- Localized PDF export with logo, structured layout, totals
- JSON-based UI translations (multi-language)
- Per‑invoice optional footer text
- Invoice status, switch easily as the process evolves
- Lightweight application, works on (almost) any specs
What You Can Use It For
| Scenario | How FOSSInvoice Helps |
|---|---|
| Freelancer with multiple brands | Keep each brand as a separate company; only one app |
| Privacy‑sensitive work | Avoid uploading client billing data to third parties |
| Offline environments | Generate invoices without an internet connection |
| Portable workflows | Carry DB + binary on encrypted USB / synced folder |
| Simple archiving | Easy backup and restore with only copying a file |
Portable Database Concept
All operational data sits in one database file:
companies, clients, invoices, invoice_items
Backups are trivial:
- Exit the app
- Copy the DB file to a backup location (cloud drive, git-crypt repo, USB, etc.)
- Restore by replacing the file
Data Ownership & Transparency
No hidden sync, telemetry, or remote API calls. Your data never leaves your computer unless you explicitly move or share it.
Who It’s For
| User Type | Fit |
|---|---|
| Solo freelancer | Strong (multi‑brand + portability) |
| Entrepreneurs | Strong (easy + clean) |
| Boutique agency | Good for lightweight billing |
| Data‑privacy advocate | Ideal – local & inspectable |
| Enterprise accounting | Not a target (no heavy compliance stack) |
Differentiators vs SaaS Invoicing
| Area | SaaS Tool | FOSSInvoice |
|---|---|---|
| Data Control | Vendor DB | Your local file |
| Offline Use | Limited | Full |
| Cost | Subscription | Free & Open source |
| Customization | Varies | Source available |
| Export Effort | Often partial | Copy one file |
Where to Go Next
| Need | Page |
|---|---|
| Install or run | Installation |
| Learn core flows | User Guide |
| Contribute / extend | Developer Guide |
| Common questions | FAQ |
| Release progress | Changelog (WIP) |
Want something specific? Open an issue on GitHub.