Ontario Mining Tax

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Ontario mining tax is imposed on profits from the extraction of mineral substances raised and sold by operators of Ontario mines.

Tax amount

The tax rate on taxable profit subject to mining tax is:

  • 10 per cent for non-remote mines, and
  • 5 per cent for remote mines.

The tax is applied to an operator's annual profit in excess of a $500,000 annual deduction, which needs to be shared by associated corporations. The deduction may be reduced on a pro-rata basis where the operator has a short tax year, the operator has a part interest in the mine, or where the mine is out of production for 60 or more consecutive days.

Mining tax exemption

A mining tax exemption on up to $10 million of profit during an exempt period is available for each new mine. The exempt period for a non-remote mine is three years, and the exempt period for a remote mine is 10 years. The mining tax exemption is also available for a major expansion of an existing non-remote mine.

To claim the mining tax exemption, complete these forms, as required for each mine, and submit a paper copy to the Ministry of Finance or an electronic PDF copy using ONT-TAXS online:

Remote mines

Remote mines are mines, opened after May 7, 1996, that are certified by the Ministry of Northern Development and Mines as remote mines.

Mining profits from remote mines are taxed at a lower preferential tax rate than non-remote mines.

An election may be made under subsection 4(4.1) of the Mining Tax Act not to be taxed as a remote mine if:

  • the mine was not treated as a remote mine in a prior tax year, and
  • the election is made in the year the mine is certified as a remote mine.


Every mining operator liable to pay tax is required to register with the Ministry of Finance. The definition of an operator includes members of partnerships and joint ventures that operate a mine.

Ontario corporation number

The Ontario corporation number is issued by the Ministry of Government Services. This number is required before you can request a mining tax account with the Ministry of Finance.

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Mining tax account

To register for a mining tax account, complete the registration form and send it to:

Ministry of Finance
PO Box 627
33 King Street West
Oshawa ON L1H 8H5

Request for Registration

If you have any questions, please call the Ministry of Finance at 1-866-ONT-TAXS (1-866-668-8297).

File a mining tax return and pay the tax

Every mine operator in Ontario needs to file a return. Each individual taxpayer must be clearly identified by the operator’s name and business number.

If you choose to file a paper return, the Ministry of Finance will mail you a personalized return during the last month of your tax year.

You can file your return and pay mining tax instalments and/or tax balances:

Payments should be in Canadian funds and be made payable to the Minister of Finance. Your Business Number should be printed on the back of the cheque or money order.

How to complete your mining tax return

Due dates

Completed mining tax returns and any supporting documents need to be filed within six months after the end of your tax year.

Functional currency

A mining operator may file its Mining Tax Return using the functional currency provisions in the federal Income Tax Act. Where the Canada Revenu Agency has accepted the functional currency reporting, the corporation may file its return with the Ministry of Finance using the same functional currency reporting.

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