The Column Tax API operates in two separate environments: production and sandbox.

The sandbox environment returns mock data and is designed for testing the functionality of the API.
The production environment lets developers store and retrieve live data from the Column Tax Application. Submissions in this environment are sent to the IRS and state agencies.

To get access to these environments, head to API access. To learn about how to create accounts and launch the Column Tax UI, head to Quick start.

API URLs

Environment	Base URL
`production`	`prod.columnapi.com`
`sandbox`	`sandbox.columnapi.com`

URLs to allow in Column Tax webview

Certain links (below) should always open in the same webview as the rest of Column Tax, except when the URL contains the special columntax-external-link=true parameter. More info in this guide.

Environment	Base URL
`production`	`https\://\*.columnapi.com`
`sandbox`	`https://_.columnapi.com` `https://_.env.bz.com`