Forms to Complete and Keep
Normally, when you electronically file tax returns, except for a few specific forms, such as elections made in the return, your clients are not required to supply the tax authorities with any other documents. However, they must keep the information slips and other supporting documents for their transmitted tax returns. The tax authorities may request these documents from those of your clients who have electronically filed their tax returns.
Taxpayer authorization
The client must sign two copies of the T183, Information Return for Electronic Filing of an Individual's Income Tax and Benefit Return and Form TP-1000.TE-V, Online Filing of the Personal Income Tax Return by an Accredited Person forms. These forms authorize the preparation and the electronic transmission of the client’s return.
The client must provide you with a signed copy of these forms and save the other for his/her files.
Documents to submit
If you are not using the client letter, you can also refer to the Client Letter - Worksheet (Jump Code: LW) to see which forms need to be submitted. When the taxpayer submits any of these forms, you may want to include a cover letter indicating that this documentation is to support an electronically filed return.