FIRPTA stands for the "Foreign Investment in Real Property Tax Act" of 1980. It is a tax law that imposes income tax on foreigners selling U.S. real estate. FIRPTA is codified in several sections of the Internal Revenue Code of 1986. Although Section 1445 is the primary one that imposes withholding obligations, other related sections exist such as Section 897, Section 1447, and Section 6039C.

A FIRPTA certificate, technically known as a certification of non-foreign status, is not something you "get" or "apply for" in the sense of a license or permit. It's actually a statement that you as the seller provide to the buyer.

The certificate generally includes information stating that you are not a foreign person, for purposes of the U.S. income tax law, and that includes your name, U.S. taxpayer identification number, and home address (not a post office box. The FIRPTA certificate, sometimes also called a FIRPTA withholding certificate, is a document that can be used in a real estate transaction to potentially reduce or eliminate the amount of tax withheld on the sale of U.S. property by a foreign person. Essentially, it's a way for the seller to prove to the IRS that they are not a foreign individual or entity, thereby exempting the transaction from FIRPTA withholding.

However, if the seller is a foreign person and the buyer has reason to believe that the seller is a foreign person, then the buyer is generally obligated to withhold 15% of the total amount realized from the sale. The amount realized is usually the purchase price. If a FIRPTA withholding certificate is obtained from the IRS prior to the sale, this withholding can be reduced or eliminated.