For 2017 and later tax years, CRA will offer online filing to trust administrators and their representatives.

In a notice, CRA says these admins and representatives “will be able to file a simple T3 Trust Income Tax and Information Return (T3RET) online […],” noting that a “simple or ‘NIL’ return means that a trust’s taxable income, total taxes payable, and refund or balance owing are $0.00.”