Legally you can’t. Those withholdings are not yours. They are payments towards your tax liability, made at the time that you earn the income. Pay as you go. It makes sense.So what you want to do is borrow money that isn’t really yours, interest free, invest it for a few months, and then pay it back the next year. Is that correct? While it’s not really permitted you can manage to get away with it. You can’t easily get away with stopping all withholding. That requires stating that you expect to pay zero taxes for the year, which you know is false. It looks suspicious and is easy for the feds to check. Instead, what you can do is reduce your withholding by claiming a large number of exemptions. That’s not nearly as suspicious. When you complete your return you’ll owe a lot of tax, which is clearly against the rules, but you’ll probably get away with it at least for a year or two and maybe longer depending on how lax the IRS is in enforcing the law on scamsters like yourself.I used to claim a large number of exemptions. It was legitimate since I actually had a lot of deductions at that time. But a couple of years I accidentally withheld too little money, more than a couple of thousand dollars. I paid the tax with my return and adjusted my withholding going forward and the IRS didn’t penalize me or question it afterwards. But if you’re talking about under withholding by a lot more than that and year after year then good luck. You might get caught, forced to pay a penalty and interest, and be flagged for special attention in the future.