What does it means - backup withholding

The person or business paying the taxpayer doesn’t generally withhold taxes from certain payments. They don’t do this because it’s assumed the taxpayer will report and pay taxes on this income when they file their federal tax return. There are, however, situations when the payer is required to withhold a certain percentage of tax to make sure the IRS receives the tax due on this income. This is what’s known as backup withholding. If a payer does backup withholding, they are required to deposit that withholding on those payments with the IRS.