A Canada Revenue Service form that must be submitted by non-residents who have received rent from real property or timber royalties in Canada and who want to file an income tax return under subsection 216(4) of the Canadian Income Tax Act. The NR6 Form must be signed by both the Canadian non-resident and his or her agent, who has been collecting the income and remitting the related taxes on behalf of the non-resident. If the undertaking is approved, the non-resident will be required to submit his or her own income tax payments by the 15th day of the month following the month during which the rental payment was paid or credited to the agent on the non-resident's behalf. Also known "Undertaking to File an Income Tax Return by a Non-Resident Receiving Rent from Real Property or Receiving a Timber Royalty," this form must be filed on or before the first day of each tax year, which usually corresponds to the calendar year, or before the first rental payment is due. This form should be completed with a list containing the annual estimated gross income, total expenses and net income for each rental property, along with each property's address. The form should also contain a list of the expenses incurred in the property's day-to-day management. This information is used in calculating the tax due.