Quick answer: Crater is a free, open-source invoicing application you can self-host, with web and mobile apps covering customers, estimates, invoices, payments and expenses. It is genuinely good at what it does and costs nothing in licence — but self-hosting is not free, and Indian GST returns and e-invoicing are not its focus. Choose it if you want to own your data and have someone who can run a server; choose a hosted product if you need Indian statutory workflows.
What Crater gives you
- Customer and estimate management, estimates converting to invoices
- Recurring invoices and payment recording
- Expense tracking and basic reporting
- Multiple companies and users
- Customisable invoice templates and tax settings
- Web application plus mobile apps
- Your data on your own server, exportable at any time
For a freelancer, agency or consultancy that bills project fees and wants a clean, self-owned system, that list is sufficient and the price is unbeatable.
What self-hosting actually costs
"Free" software has a running cost, and it is worth stating honestly before you commit:
| Cost | Reality |
|---|---|
| Server | A small VPS monthly — see web hosting and our VPS hosting guide |
| Setup | Installation, domain, TLS certificate, mail sending configuration |
| Backups | Automated, tested, off-server. Nobody else will do this for you |
| Updates | Security patches applied promptly; an unpatched public app is a liability |
| Email deliverability | Invoices landing in spam is a real and common problem |
| Someone who can fix it | The binding constraint. If nobody on your team is comfortable with a Linux server, the true cost is a contractor on call |
If you have that capability, the total is modest. If you do not, a hosted product will be cheaper in practice than a self-hosted one you cannot maintain.
The Indian compliance question
This is the deciding factor for most Indian businesses. Crater handles taxes generically. What it is not built for:
- GSTR-1 and GSTR-3B preparation in the formats the Indian portal expects
- E-invoicing (IRN) generation for businesses above the turnover threshold
- E-way bills
- HSN/SAC reporting at the required digit level
- TDS on receivables and payables
- Reverse charge, composition scheme and place-of-supply handling
You can issue an invoice that carries the right particulars, but the return and e-invoicing workflow will be manual or handled elsewhere. For a small services business below the e-invoicing threshold whose CA files returns from the books anyway, that may be entirely acceptable. For a trading business above the threshold, it is not. See our e-invoicing and e-way bill guide.
The alternatives worth weighing
If "free" is the requirement: Zoho Invoice is free, hosted, and built with Indian GST in mind — for most Indian users it is the more practical free option than self-hosting. See our Zoho Invoice guide.
If "open source and self-hosted" is the requirement: ERPNext is a far broader open-source system with an active Indian community and India-specific compliance modules, at the cost of much greater complexity. Frappe Books is the lighter desktop accounting sibling.
If you need Indian compliance without running servers: Zoho Books, TallyPrime, BUSY, Vyapar. See best billing software for small business.
Who Crater is genuinely right for
- A freelancer or small agency billing services, comfortable with a VPS, who wants to own the data.
- A developer or technical founder who will host it alongside other applications they already run.
- A business with data-residency or privacy requirements that make a hosted SaaS unattractive, and the capability to run infrastructure properly.
If none of those describes you, the honest recommendation is a hosted product — the licence saving does not cover the operational cost.
FAQs
Is Crater Invoice free?
Yes. Crater is open-source and free to licence, with web and mobile applications. Self-hosting costs money for a server, setup, backups, updates and email deliverability, and requires someone who can maintain it — so it is free in licence, not free in total cost.
Does Crater support Indian GST and e-invoicing?
Not as a built-in workflow. Crater handles taxes generically and can produce an invoice carrying the required particulars, but GSTR-1 and GSTR-3B preparation, e-invoicing IRN generation, e-way bills and TDS are not its focus. Businesses above the e-invoicing threshold should use a product built for Indian compliance.
What is the best free invoicing software in India?
For most Indian businesses, Zoho Invoice — it is free, hosted, and built with Indian GST in mind, so there is no server to maintain. Crater is the better choice specifically when you want open source and self-hosted control over your data and have the capability to run it.
Crater or ERPNext?
Crater is a focused invoicing application, quick to set up and easy to understand. ERPNext is a full open-source ERP with accounting, inventory, manufacturing and India-specific compliance modules, plus an active Indian community — far more capable and far more complex. Choose Crater for invoicing only; ERPNext when you need a system of record for the business.
Is self-hosting invoicing software a good idea for a small business?
Only if someone on the team is genuinely comfortable maintaining a Linux server, including backups and security updates. An unpatched public-facing application holding customer and financial data is a real liability. Where that capability does not exist, a hosted product is cheaper in practice despite the licence fee.
Next step: get a free matched invoicing and accounting shortlist for your business and compliance needs.
