On California law applying: It's complicated. California courts have held that California employment laws can apply to California employers even for out-of-state employees in certain circumstances. See Sullivan v. Oracle Corp. However, this is fact-specific.
The safer approach: create a Texas-specific employment arrangement that complies with Texas law while being mindful of any California obligations that might still apply.
On the tax withholding issue: Your employee will need to file for a refund of California taxes withheld for the period he was in Texas. You'll need to issue corrected W-2s. There may be penalties for failure to withhold Texas unemployment taxes, but since Texas has no income tax, at least you don't have that issue.
Immediate steps you should take:
- Contact your payroll provider TODAY and update his work location
- Register with Texas Workforce Commission for unemployment insurance
- Get Texas workers compensation coverage
- Consult with a multi-state employment attorney about your broader compliance obligations
- Consider whether you need to register as a foreign entity in Texas
- Update your employee handbook to require pre-approval for out-of-state moves