Every new employee must complete a Form W-4. If a Form W-4 is not completed, the tax withholding will default to.The Employee's Tax Withholding Allowance Certificates are the Federal Form W-4 and California. Attach copies of your pay stubs for the last two months and proof of any other income. Learn about income tax withholding and estimated tax payments. NEW TAX COLLECTOR OFFICE HOURS: The Tax Collector's office is open to the public Monday – Friday from am – pm, excluding holidays. Welcome! San Bernardino County - Local Forms.