The purpose of withholding tax is to collect income tax at the source, as wages are earned, as part of the state's "pay-as-you-go" plan of income tax collection.
If you are a nonresident who owns and is selling or transferring real property and associated tangible personal property in Maryland, you must make a tax withholding payment to the local Clerk of the Circuit Court or the Maryland Department of Assessments and Taxation (SDAT). The payment must be made before the deed or other instrument of transfer is recorded with the court clerk or filed with SDAT.
For a nonresident individual, the payment is 7.5% of the total property sale payment made to the individual. A nonresident entity must make an 8.25% payment. See Withholding Requirements for Sales of Real Property by Nonresidents.