No, The employer may not change your Federal Withholdings without your consent unless an order from the IRS to withhold taxes.
The IRS allows you to change the number of your allowances as frequently as you need to, Exemption allowances are entered on Form W4 You can complete Form W-4 to your employer to withhold the correct federal income tax from your pay. If too little is withheld, you will owe tax when you file ..
