You send the 8288A to IRS, And I think it takes them a couple of months to approve it (maybe longer with COVID-19). The form must provide a calculation of the maximum tax liability that may be imposed on the disposition of the property and should be sent to the IRS after a contract is signed on the property, but before the settlement date. A copy of the 8288-B is provided to the buyer/buyer’s agent, allowing him or her to retain the funds until he/she receives an approval letter from the IRS to remit any of the excess withholding tax back to the nonresident seller.