Billsby and Kill Bill both handle subscription billing, but they trade off differently between convenience and control. Billsby is a hosted SaaS billing…
| Billsby | Kill Bill | |
|---|---|---|
| Primary category | Invoicing | Invoicing |
| Rating | Not documented | Not documented |
| Pricing model | Subscription + usage-based | Open Source (with paid enterprise tier) |
| Starting price | $45/month (Core plan, plus 0.4% of revenue over $15,000/month) | Free |
| Free plan | Yes | Yes |
| Free trial | Not documented | Not documented |
| Platforms | Web | Not documented |
| Team collaboration | Not documented | Not documented |
| AI features | Not documented | Not documented |
| Public API | Yes | Yes |
Pricing Model
Billsby: Billsby charges $45/month plus 0.4% of revenue over $15,000/month on its Core plan, and $135/month plus 0.5% of revenue over $30,000/month on Pro.
Kill Bill: Kill Bill's core platform is entirely free and open source under Apache 2.0, with no per-transaction or revenue-percentage fees.
Revenue-percentage billing fees scale with a company's success and can become a meaningful cost at high transaction volume, unlike a flat self-hosted infrastructure cost.
Hosting and Operational Responsibility
Billsby: Billsby is a fully hosted SaaS product; users don't manage servers or deployments.
Kill Bill: Kill Bill is self-hosted via Docker or Kubernetes in your own infrastructure, and requires engineering resources to deploy, operate, and maintain.
Self-hosting shifts operational burden (uptime, upgrades, security patching) onto the adopting team in exchange for infrastructure control.
Payment Gateway and Tax Support
Billsby: Billsby supports multiple payment gateways including ACH processing, but only on the Pro plan; tax compliance is also a Pro-plan feature.
Kill Bill: Kill Bill has native plugin support for Stripe, Adyen, PayPal, Braintree, and other gateways, plus tax engine integrations with Avalara and Vertex, available in the free core.
Whether gateway and tax capabilities are gated behind a paid tier or available in the free core affects total cost for businesses needing those features from day one.
API and Customization Access
Billsby: Billsby offers full API access on its Pro plan for custom integrations; the Core plan does not include it.
Kill Bill: Kill Bill provides an extensible plugin architecture for building custom integrations and modifications as part of the free, open-source core.
Gating API access behind a higher-priced plan limits how deeply a lower-tier customer can integrate billing with the rest of their stack.
Track Record and Maturity
Billsby: Billsby is rated 4.8 stars on G2 and marketed as the '#1 Rated Subscription Billing Software,' but its founding year and headquarters are not disclosed.
Kill Bill: Kill Bill was founded in 2010 and has been in production for over 15 years, with a documented Apache 2.0 license history.
A long production track record signals stability for mission-critical billing infrastructure that businesses depend on for revenue.
| Feature | Billsby | Kill Bill |
|---|---|---|
| Subscription products, plans, cycles | Available | Available |
| Usage-based / prepaid / postpaid billing | Not documented | Available |
| Automated dunning | Available | Not documented |
| Multi-tenant support | Not documented | Available |
| Feature | Billsby | Kill Bill |
|---|---|---|
| Multiple payment gateways | Limited | Available |
| Tax compliance / tax engine integration | Limited | Available |
| Full API access | Limited | Available |
| Feature | Billsby | Kill Bill |
|---|---|---|
| Free tier | Available | Available |
| Revenue-percentage fees | Available | Unavailable |
| Self-hosted deployment | Unavailable | Available |
| Admin UI included | Not documented | Available |
Starting price reflects the lowest paid tier, not the full cost for every team size or usage level.
Pros
Cons
Pros
Cons
No, Kill Bill's core platform has no per-transaction or revenue-percentage fees since it's free and self-hosted; Billsby charges 0.4% on revenue over $15,000/month on its Core plan and 0.5% over $30,000/month on Pro.
Yes, Kill Bill requires engineering resources to deploy, operate, and maintain since it's self-hosted via Docker or Kubernetes, unlike Billsby, which is a fully hosted SaaS product.
Full API access is included on Billsby's Pro plan ($135/month plus 0.5% on revenue over $30,000/month), not the $45/month Core plan; Kill Bill includes API-level extensibility through its plugin architecture in the free core.
Yes, Kill Bill has native plugin support for Stripe, Adyen, PayPal, Braintree, and other payment gateways, available without a paid tier.
Yes, Billsby offers a free plan that allows unlimited testing and setup before going live, with no time limit.
Kill Bill has no official low-code hosted option from the core project itself, though third-party providers offer managed hosting; Billsby, by contrast, is hosted SaaS by default.
Read the full Billsby review · Read the full Kill Bill review