How do I file my Ontario tax return online?

Ontario residents file their personal income tax return (T1) using the CRA's NETFILE service, which allows you to submit your return electronically through CRA-certified tax software. There is no separate Ontario online filing system — the T1 covers both federal and provincial tax, and NETFILE transmits everything to the CRA at once.

The process involves completing your T1 return in certified software (many options are free for simple returns under certain income thresholds, including the CRA's own File My Return program for eligible simple filers), reviewing it for accuracy, and clicking "submit" to transmit it. You receive a confirmation number from the CRA once the return is accepted. Most Canadians receive their notice of assessment within two weeks if filing electronically.

To use NETFILE, you need a Social Insurance Number (SIN) and, in some cases, information from your prior year's notice of assessment for verification. First-time filers may not be able to use NETFILE and may need to file a paper return or visit a tax clinic. If you have complex income (self-employment, foreign assets, multiple investment accounts), professional software or a tax professional is recommended to avoid errors.