Looking for open source VoIP billing software you can actually run in production? The strongest fully open options in 2026 are CGRateS, a carrier-grade charging engine, and ASTPP, a FreeSWITCH-native softswitch and biller. MagnusBilling and jBilling follow as open-core tools that keep some features in paid commercial tiers. Here is how the leading projects compare.
Why VoIP providers pick open source billing
If you run an ITSP, a calling-card service, or a wholesale VoIP business, billing is the part that actually pays the bills. You need accurate call rating, prepaid credit control, postpaid invoicing, and clean CDR records. Open source billing software gives you all of that without a per-seat license, and you keep full control of your rating logic and customer data. For a deeper look at the trade-offs, read our guide on open source VoIP billing software versus proprietary.
How we ranked these tools
We put fully open source projects ahead of dual-model tools. A fully open project ships its complete feature set under a free license, so you can self-host, audit, and modify it without hitting a paywall. A dual-model project keeps a community core open but locks some modules behind a paid commercial edition. Both can work well, but full open source gives you more freedom and fewer surprises, so it ranks higher here.
Open source VoIP billing software at a glance
| Software | License | Telephony engine | Model | Best for |
|---|---|---|---|---|
| CGRateS | AGPL-3.0 | Engine-agnostic | Fully open | Carrier-grade operators |
| ASTPP | AGPL-3.0 | FreeSWITCH | Fully open | FreeSWITCH ITSPs and resellers |
| A2Billing | MPL-based | Asterisk | Fully open (aging) | Legacy Asterisk calling cards |
| MagnusBilling | LGPL-3.0 core | Asterisk | Open core plus paid modules | Active Asterisk resellers |
| jBilling CE | Community license | Engine-agnostic | Open core, now EarnBill | Subscription and recurring billing |
Fully open source VoIP billing software
1. CGRateS
CGRateS is the most powerful fully open option on this list. It is a real-time charging engine written in Go, released under AGPL-3.0, and it stays engine-agnostic with connectors for FreeSWITCH, Asterisk, Kamailio, OpenSIPS, and Diameter. You get online and offline charging, balance management, least-cost routing, and fraud detection at carrier scale. The catch is that CGRateS is an engine, not a finished admin panel, so you need developer skills to wire it into your stack. If you want raw billing power and high throughput, start here. Repo: github.com/cgrates/cgrates.
2. ASTPP
ASTPP is built specifically for FreeSWITCH, which makes it a natural fit if your platform runs on the same engine we use at ICT Innovations. It is AGPL-3.0, written in PHP on the CodeIgniter framework, and it acts as both a Class 4 and Class 5 softswitch and a billing system. You get prepaid and postpaid billing, real-time rating, DID billing, multi-currency support, and reseller multi-tenancy out of the box. Development is still active. If you run FreeSWITCH and want a ready-made biller rather than a toolkit, ASTPP is the one to try first. Repo: github.com/iNextrix/ASTPP.
3. A2Billing
A2Billing is the veteran of Asterisk billing, known for calling cards, prepaid and postpaid plans, callback, and least-cost routing. It is open and still widely deployed, but active development has slowed and the codebase shows its age. Pick it only if you already depend on it or you maintain a legacy Asterisk calling-card service. New projects are better served by the more active options above, or by MagnusBilling below. Repo: github.com/Star2Billing/a2billing.
Open core billing software with commercial tiers
4. MagnusBilling
MagnusBilling is the most actively maintained biller in the Asterisk family and a modern successor to A2Billing. The community core is open under LGPL-3.0, and it covers real-time prepaid and postpaid billing, rate cards, DID billing, calling cards, SIP trunk provisioning, and reseller management. It sits in the dual-model tier because some advanced modules live behind a paid commercial offering. If you run Asterisk and want something that is still updated in 2026, MagnusBilling is a safe pick. Repo: github.com/magnussolution/magnusbilling7.
5. jBilling (Community Edition)
jBilling is a Java-based billing platform that handles subscriptions, recurring invoicing, and CDR mediation. It is engine-agnostic rather than VoIP-specific, so it suits service billing more than real-time call rating. Note that the original team has moved its focus to a commercial product called EarnBill, and the open community edition is now legacy. Treat it as a starting point for general subscription billing, and check the project status before you commit to it. Site: jbilling.com.
How to choose the right one
Match the tool to your telephony engine first. If you run FreeSWITCH, ASTPP or CGRateS will fit best. If you run Asterisk, MagnusBilling is the active choice, with A2Billing as the legacy fallback. For carrier-scale charging across mixed infrastructure, CGRateS stands alone. If you mainly need subscription invoicing rather than per-second call rating, a general biller like jBilling can do the job. It also helps to understand the engines themselves, so our comparison of open source SIP servers like Asterisk, Kamailio, and OpenSIPS is a useful companion read. Once billing is live, keeping an eye on call quality matters too, which is where open source VoIP quality monitoring tools come in.
Where ICT Innovations fits
We build open source VoIP on FreeSWITCH and our own ICTCore framework, so we spend a lot of time helping providers connect billing to live call flows. If you want a custom billing integration, a FreeSWITCH-native setup, or help tuning rating and CDR pipelines, our team can do that work for you. Explore our open source VoIP services or open a ticket to talk through your project.
Frequently asked questions
Is open source VoIP billing software really free?
The software itself is free to download and run under its open license. You still pay for the server, your own setup time, and any custom development or support you choose to add. Fully open tools like CGRateS and ASTPP have no paid feature tiers, while open-core tools may charge for advanced modules.
Which open source billing software works with FreeSWITCH?
ASTPP is built natively for FreeSWITCH, and CGRateS connects to it through a dedicated connector. Both are strong matches if your platform runs on FreeSWITCH.
What is the difference between fully open source and open core billing?
Fully open source ships every core feature under a free license. Open core keeps a free community edition but moves some features into a paid commercial version. We rank fully open projects higher because they give you complete control with no paywall.
Can open source billing software handle both prepaid and postpaid?
Yes. ASTPP, MagnusBilling, and CGRateS all support prepaid credit control and postpaid invoicing, which covers most ITSP and reseller billing needs.
Is A2Billing still maintained in 2026?
A2Billing still works and remains in production at many providers, but its active development has slowed. For a maintained alternative on Asterisk, most teams now move to MagnusBilling.