No, it is not legal, your employer is engaging in tax evasion and could go jail for this, and also pay considerable fines: furniture sales are subject to sales tax, so he has to charge this and pay it to the  state; and there is no right to pay employees "under the table" and not pay the appropriate taxes on their income. All wages must have the proper withholding taken out, even if paid in cash.Note that if you are being paid "under the table":1) You'l have to pay all the amounts that should have been withheld yourself, or else you'll be violating your tax obligations;2) If he's not making contributions for social security and unemployment, you are not receiving social security credits and are not eligible for unemployment benefits if you are terminated.3) He's also presumably not maintaining worker's compensation coverage, in case of on-the-job injury. So what you employer is doing is not just illegal, it's hurting you and your coworkers. Unless you're willing to put up with this, you should either speak to an attorney about possibly suing to get what should have been paid for you, and/or speak to your state's department of labor.