Did you know that if you buy real estate in the U.S. from a foreign owner, you may have to withhold a big chunk of the sale price and send it to the IRS?

This is required by a law called FIRPTA (the Foreign Investment in Real Property Tax Act), which is designed to make sure that foreigners who sell U.S. property don’t skip off without paying taxes.

In the past, a buyer generally had to withhold 10% of the sale price and send it to the IRS. Effective February 15, 2016, the withholding rate has gone up to 15%.

There are exceptions, though, if the buyer is going to live in the property as a primary residence. In that case, the withholding rate is 10% if the sale price is under $1 million, and withholding is waived altogether if the sale price is under $300,000.

Generally, the withholding will be handled by whoever is acting as the settlement agent, but it’s good to be aware of the rules.

If you’re a seller who’s a U.S. citizen, you may be asked to sign a certification that you’re not a “foreign person” and thus withholding isn’t necessary.

If you’re selling property and you’re not a U.S. citizen, it’s possible to apply to the IRS for permission to reduce the amount of the withholding to the amount of tax that’s expected to be due; the IRS is usually good about approving such requests quickly.