The Open-Source Invoicing Core, Hosted for You From $9/mo.

Both are free if you self-host, and both publish their full source on GitHub. The two practical differences are the license and the hosting model. SolidInvoice uses the MIT license, which is one of the most permissive in software and has no copyleft clause. InvoiceShelf uses AGPLv3, which can require you to publish your own modifications under the same license if you expose a modified version to users over a network. Most SolidInvoice users skip self-hosting entirely and use the managed cloud plan from $9/mo instead; InvoiceShelf is self-host only.

Yes. The self-hosted edition is the same codebase as the cloud version, with no usage caps and no license keys. Unlimited invoices, unlimited clients, recurring billing, online payments, multi-currency, team roles, and the REST API are all included. Invoice and quote templates are the one cloud-only feature. Otherwise the cloud plans add managed hosting, automatic updates, and backups.

If you only run InvoiceShelf for internal invoicing without modifying it, AGPLv3 has no practical impact. The license becomes relevant when you change the code or build a product on top of it. AGPLv3 can require you to publish your modifications under the same license, including changes you only expose over a network. MIT has no such requirement, which is why many agencies, SaaS teams, and businesses with compliance reviews prefer it.

SolidInvoice does not yet have a built-in InvoiceShelf importer, that is on the roadmap. The fastest path is to add your active clients into SolidInvoice manually, then start sending new invoices from the new system while keeping your InvoiceShelf instance for historical records. Most users complete the switch in an afternoon. Reach out to support if you need help with the transition.

InvoiceShelf has dedicated iOS and Android apps. SolidInvoice does not currently ship a native mobile app, but the web app is fully responsive and works well on phones and tablets. If a native mobile app is a hard requirement for you, that is one area where InvoiceShelf is currently ahead.

Yes. SolidInvoice has been in active development since 2013, with the full commit history and release notes available on GitHub. The same team maintains the open source repo and the hosted cloud product, so the codebase is exercised in production every day.