IRS can send the information to your clients(informing them of the levy and) asking them to make the payment to the IRS instead of you. IRS gets the information from the Form 1099 filing.
It is one of the ways IRS collects unpaid tax liabilities.
Let me know if you have any question.
Please note: This advice is provided with the understanding that all the relevant facts have been provided by you. Any change in facts might affect the advice given and hence may not be relied on in such cases. Nothing contained in this reply was intended or written to be used, can be used by any taxpayer, or may be relied upon or used by any taxpayer for the purposes of avoiding penalties that may be imposed on the taxpayer under the Internal Revenue Code of 1986, as amended.
Yes, they are required to pay the IRS the amount that is actually due and payable to you.
If the guy cutting your lawn owed IRS taxes and the IRS levied that guy than they can required you to pay the amount to the IRS (the amount that you would otherwise be obligated to pay to the lawn guy).
IRS is not asking you to make the payment from your pocket. It is asking you to pay the amount that you would otherwise pay to that person.