What Corporates Have to Make Corporation Internet Filing.

All corporations, with a few exceptions* can use Corporation Internet Filing to file their 2002 and later years corporation income tax returns.
Beginning with tax years ending after 2009, corporations with gross revenues more than $1 million have to Internet file their T2 Corporation Income Tax Return using CRA approved commercial software.

*
Exceptions apply to Insurance Corporations, Non-resident corporations, Corporations reporting in functional currency and Corporations that are exempt from tax payable under section 149 of the Income Tax Act.
It means that the Corporation Internet Filing service can’t be used for a tax returns for any year prior to the 2002 tax year and or a tax return for any Insurance corporation.

cra-arc.gc.ca