Compare Kill Bill and invoice-api on pricing, features, platforms, and ratings — both Invoicing tools, Open Source (with paid enterprise tier) vs Freemium…
At a Glance
Kill Bill
invoice-api
Primary category
Invoicing
Invoicing
Rating
Not documented
Not documented
Pricing model
Open Source (with paid enterprise tier)
Freemium
Starting price
Free
18
Free plan
Yes
Yes
Free trial
Not documented
Yes
Platforms
Not documented
Not documented
Team collaboration
Not documented
Not documented
AI features
Not documented
Not documented
Public API
Yes
Yes
Pricing Compared
Starting price reflects the lowest paid tier, not the full cost for every team size or usage level.
No vendor lock-in and full ownership of billing data
Highly customizable via plugin architecture for gateways, tax, and notifications
Proven at scale in production since 2010
Optional Aviate enterprise layer for teams wanting managed support
Cons
Requires engineering effort to deploy, configure, and maintain self-hosted
No published pricing for the Aviate enterprise tier
Steeper learning curve than hosted SaaS billing competitors like Chargebee or Recurly
Smaller ecosystem and community than some commercial alternatives
Payment gateway and tax integrations depend on plugin maturity
invoice-api
Pros
Covers a wide range of EU e-invoice formats (XRechnung, ZUGFeRD, Factur-X, FatturaPA, Peppol) from a single API
Free tier with no credit card required, plus a live API playground for testing before committing
Pre-built integrations for major shop platforms (Shopify, WooCommerce, Shopware, Magento, PrestaShop, JTL-Shop) and automation tools (n8n, Zapier, Make, Airtable, HubSpot)
Includes GoBD-compliant archiving with 10-year retention, addressing a compliance need many teams would otherwise build separately
Transparent, published self-serve pricing with a 14-day trial on paid tiers
Cons
Free tier is limited to 20 API calls total, which only covers basic evaluation, not real usage
Paid tiers are metered by API call volume, so cost can scale quickly for high-volume invoicing
Site content is presented primarily in German with an English toggle, and depth of English documentation may lag the German version
As a developer API rather than an end-user application, it requires engineering effort to integrate rather than being usable out of the box by non-technical teams
Use Cases
Kill Bill
Custom recurring billing infrastructure — Engineering teams build tailored subscription billing logic without vendor lock-in.
Usage-based and metered billing — Companies with consumption-based pricing models implement custom metered billing workflows.
Multi-tenant white-label billing — Platforms and marketplaces run billing for many tenants or resellers from a single installation.