The Canadian Federal government has introduced the Underused Housing Tax Act (UHT) to prevent foreign buyers from purchasing residential properties and leaving them vacant. The act came into effect on January 1, 2022, and the filing requirements and forms were recently released by the Canada Revenue Agency (CRA). Note that this is not the same as the Toronto Vacant Home Tax. It is important to note that the UHT applies to many Canadian property owners, including Canadian-controlled private corporations, partnerships, and trustees who own residential properties on behalf of joint ventures or corporations that they are shareholders in. Residential properties that fall under UHT include condos, single-family homes, semi-detached houses, duplexes, triplexes, and commercial properties that have more than 50% residential use and have three units or fewer. However, certain types of properties and owners are excluded from the act. There are also exemptions available based on the type of owner, availability, location, and use of the residential property, and the occupant. You must file the tax return regardless if you are exempted or not. Failure to file the UHT return for affected owners can result in a penalty of $5,000 for individuals and $10K for corporations.
You can refer to the following URL from CRA for more information.