# Sandbox Linear Callboxes

Use the following set of credentials to add virtual Linear callboxes to your Seam [sandbox workspace](https://docs.seam.co/latest/~/revisions/DFdrUdS2jQOnbJTNDT5a/core-concepts/workspaces#sandbox-workspaces):

| Phone Number | Master Code | Unit number |
| ------------ | ----------- | ----------- |
| +18888888888 | 123456      | 1           |