- Can I file my CT23 on a diskette?
- When is the tax return due?
- What information must be included with the tax return?
- Are any corporations exempt from filing a corporations tax return?
- Which corporations qualify to use the short form CT23 Tax Return?
- How do I make corrections to my return?
Can I file my CT23 on a diskette?
Diskette Filing (D-File), which was implemented by the ministry in June 1995, is the original method of filing the CT23 return in an electronic format. With D-File, the CT23 return is stored on a diskette and submitted to the ministry.
For more information on D-File please see Information Bulletin 4003R.
For a list of software vendors please see our Diskette Filing (D-File) page.
When is the tax return due?
All corporations that have a permanent establishment in Ontario are required to file a Corporations Tax Return within six months of the corporation's taxation year end. The Ministry of Finance considers the tax return filed the day the return is received by the ministry - not the date the return was mailed. A late filing charge will be applied if the return is received after the due date. The late filing charge is based on the unpaid balance of tax at the return due date.
What information must be included with the tax return?
The CT23 Corporations Tax Return must be completed and signed by an officer of the corporation. Copies of the corporation's financial statements completed in accordance with Generally Accepted Accounting Principles, and any Ontario schedules should be included with the tax return. The federal T2 Corporate Income Tax Return and related schedules must be included with the return sent to the Ministry of Finance if the taxation year ends before January 1, 2001. For taxation years ending after December 31, 2000, corporations are no longer required to file a copy of the federal T2 and related schedules, provided the federal documents have been filed with the Canada Revenue Agency.
Are any corporations exempt from filing a corporations tax return?
Please refer to the Exempt From Filing Declaration Form on page 2 of the CT23 Corporations Tax and Annual Return [PDF - 292 KB] or to Information Bulletin 4001R1 "Combined Return, Short-Form Return and the Exempt from Filing Policy for Corporations" dated November 2003 for the conditions which must be met in order to be exempt from filing for a particular taxation year.
You may also contact the Desk Audit Section of the Tax Compliance Branch at one of the following telephone numbers:
- Pickering : 905 420-9363
- Toll Free within Ontario : 1 866 805-7702
- Fax : 905 837-3800
Which corporations qualify to use the short form CT23 Tax Return?
The criteria for determining whether or not a corporation can use the CT23 Short Form Corporations Tax Return is provided by Information Bulletin 4001R1 "Combined Return, Short-Form Return and the Exempt from Filing Policy for Corporations" dated November 2003.
How do I make corrections to my return?
File an amended return for the taxation year in question. Alternatively, a letter detailing the required changes may be sent to:
Ministry of Finance
Tax Compliance Branch
Desk Audit
33 King St W
PO Box 627
Oshawa ON L1H 8H6
For Canadian-controlled private corporations, corrections must be made within four years from the date of mailing of a notice of original assessment. For all other corporations, corrections must be made within five years from the date of mailing of an original assessment. Where the correction relates to a discretionary deduction (e.g. capital cost allowance claim), the ministry will only make the correction under the circumstances outlined in Interpretation Bulletin 3009R "Statute-Barred Periods" dated October 2001 and provided the year is not statute-barred. If additional information is required, please contact the Desk Audit Section of the Tax Compliance Branch.
