Tax integration

Kill Bill and Vertex

Add sales tax from Vertex O Series to every Kill Bill invoice. Tax is calculated when the invoice is generated and added as separate tax lines. The plugin is open source and maintained by the Kill Bill team.

Last updated: October 2026

Read the plugin guide
How it works
Short answer

Does Kill Bill work with Vertex?

Yes. The Vertex plugin sends each invoice's line items to Vertex Indirect Tax O Series, through its REST API, when the invoice is generated. Vertex returns the sales tax, and Kill Bill adds it as TAX lines on the invoice. Kill Bill does not file tax returns.
Plugin
Open source, Apache 2.0
Maintained by
The Kill Bill team
Vertex product
Indirect Tax O Series, REST API v2
Calculates
Sales tax, delegated to Vertex
On the invoice
TAX lines
Configuration
Per tenant: URL, client ID and secret, company
How it works

From Invoice to Tax Lines

Invoice generated Recurring, usage, one-off Invoice line items Vertex plugin Company and division Per-tenant credentials TAX invoice items O Series REST API v2 line items tax Tax is computed when the invoice is generated and added as its own lines.
  1. 1
    Connect VertexUpload the Vertex API URL, client ID and client secret for the tenant, and optionally the company name and division.
  2. 2
    Generate the invoiceKill Bill sends the invoice line items to Vertex O Series.
  3. 3
    Add tax linesVertex returns the sales tax. Kill Bill adds it as TAX items on the invoice.
Who does what

Vertex Calculates, Kill Bill Invoices

Vertex holds the tax rules and rates. Kill Bill builds the invoice, asks for the tax and records it.
TaskVertexKill Bill
Tax rates and jurisdiction rulesVertex·
Tax calculationVertex O Series·
Invoices and line items·Kill Bill
Tax lines on the invoice·Kill Bill
Credentials per tenant·Kill Bill
When invoices are generated·Kill Bill
Other tax engines

Choose the Tax Engine That Fits

Kill Bill works with several tax engines. Pick one per tenant.
Avalara
US sales tax by state, county and city, with Avalara tax codes and exemptions.
Kintsugi
Sales tax through Kintsugi, set up from the Kintsugi app.
Aviate Tax
VAT or GST rates you set per product and country, part of Aviate.
Resources

Guide and Code

Plugin guide and source codekillbill/killbill-vertex-plugin on GitHub
Kill Bill pluginsHow plugins work, on docs.killbill.io
Tax, invoicing and complianceHow Kill Bill handles tax
FAQs

Frequently Asked Questions

Does Kill Bill integrate with Vertex?
Yes. The open source Vertex plugin, maintained by the Kill Bill team under the Apache 2.0 license, sends invoice line items to Vertex Indirect Tax O Series and adds the returned sales tax as TAX lines on the Kill Bill invoice.
Which Vertex product does the plugin use?
Vertex Indirect Tax O Series, through its REST API v2.
How is the plugin configured?
Per tenant, or globally: the Vertex API URL, client ID and client secret are required. A company name and a company division can be added.
Can different tenants use different Vertex accounts?
Yes. The configuration can be uploaded for each tenant, so each tenant can point to its own Vertex credentials.
Does Kill Bill file tax returns?
No. Kill Bill adds tax to invoices and keeps the records. Filing stays with your tax provider or your finance team.
Does the Vertex plugin cost anything?
The plugin is open source and free. You need your own Vertex account, under Vertex's terms.