Assessment Work

Assessment work refers to the exploration activities that must be done on mining claims to maintain the right to explore for minerals.  The costs of exploration activities are converted to Assessment Work Credits. These credits may be:

  • Applied to the claim where the work was done in the year in which it was done.
  • Assigned to an adjoining claim in the year in which the work was done.
  • Banked, to be applied in following years to the claim where the work done or assigned to an adjoining claim.

Each year Assessment Work Credits must be applied or assigned to each claim held. Methods permitted include:

  • Filing geoscience assessment work.
  • Distributing banked assessment work credits or
  • Making payments in place of assessment work.

If Assessment Work requirements are not met for a mining claim, it will become forfeit and will be reopened for claim staking.
In order for assessment work to be valid, it must be submitted, recorded and approved by the Minister.  It must meet the terms of the Assessment Work Regulation (Ontario Regulation 6\96.)

Valid Types of Work

Exploration activities that can be used for assessment work credit include:

  • Performing physical work such as overburden stripping and bedrock trenching.
  • Conducting geophysical, geological and geochemical surveys.
  • Performing exploratory drilling.
  • Rehabilitation work that has been approved by the Ministry
  • Conducting Aboriginal consultation.
  • Providing Global Positioning System (GPS) georeferencing data for unpatented mining claims recorded prior to November 1, 2012.

It is also possible, in certain circumstances, to make cash payments in place of actual assessment work. 

Although most assessment work occurs after a mining claim is staked and recorded, exploration activities that were performed up to 12 months prior to the recording of a mining claim are also eligible for assessment credit.

For more information on valid types of exploration activity see Assessment Work (Ontario Regulation 6/96) or contact a Geoscience Assessor in the Provincial Recording Office.

Amount of Work Required

A mining claim holder is not required to file any geoscience assessment work between the initial recording of a mining claim and the first anniversary date of the mining claim. By the second anniversary of the recording of a claim and by each anniversary thereafter, a minimum of $400 worth of exploration activity per claim unit must be reported to the Provincial Recording Office.

Banked credits are not automatically applied to mining claims. It is the claim holder’s responsibility to maintain mining claims by filing an Application to Distribute Banked Assessment Work Credits form before any due date.

Payments in place of reporting assessment work may also be used to meet yearly assessment work requirements, provided the payments are not used for the first unit of assessment work and consecutively thereafter.  Payments cannot be banked to be carried forward for future use.  Other restrictions may apply.

Performing Assessment Work

Surface rights include all rights to a piece of land which are not mineral rights.

For work conducted before November 1, 2012:
The Mining Act requires mining claim holders to notify all persons who own surface rights to any part of the land located within the mining claim a minimum of 24 hours before performing any assessment work.  Proof of giving this notice must be included with the submission of assessment work.

For work conducted on or after April 1, 2013:
Assessment work involving:

  • Geophysical surveys requiring a power generator.
  • Line cutting.
  • Mechanized drilling for the purposes of obtaining rock or mineral samples.
  • Mechanized surface stripping (overburden removal).
  • Pitting and trenching (of rock).

requires an exploration plan or exploration permit before it can be performed.

Consultation with Aboriginal communities, as identified by ENDM, is encouraged before early exploration activities are undertaken. Some expenses related to consultation with Aboriginal communities can be submitted for assessment work credit.

Filing Assessment Work

To file assessment work, you must submit:

  • An assessment work submission form.  
  • A written report that outlines the exploration activity that occurred throughout the year. 
  • All relevant technical documentation such as drill logs, geological reports and maps or sketches.

Assessment work can be submitted online using the Electronic Assessment System (EAS) (decommissioned) or mailed, faxed or delivered to Provincial Recording Office.

Filing submissions of Assessment Work (Section 6 of Ontario Regulation 6/96):

Assessment Work must be reported.  It can be filed:

  • on paper (paper forms and paper report/maps)
  • digitally (paper forms and report/maps on CD or DVD),
  • electronically via the Electronic Assessment System (EAS) (decommissioned)

You must file one of the following:

  • If the work was done after the claim was recorded, submit one copy of the form Assessment Work Performed on Mining Lands (form #0241).
  • If the work was done before the claim was staked and recorded, submit one copy of the form Assessment Work Performed before Recording a Claim (form #0240)

You must also submit:

  • One copy each of the technical report(s) and map(s) describing the assessment work and results being filed for assessment credit.

You may also have to file one or more of the following:

  • If assessment work credits are being assigned from one or more claims to other claim(s) you must submit a legible sketch or claim map showing the contiguity of your claims.
  • If you are filing work on behalf of the recorded holder(s) you must submit an Agent authorization letter(s)
  • If including someone else’s claim(s) in the report, and you are distributing credits amongst claims, you must submit proof of beneficial interest, such as an option agreement on the property.
  • If work was performed prior to November 1, 2012 and someone holds the surface rights other than the crown or the recorded holder, include a copy of the Notice of Intention to Perform Assessment Work (form # 0242) sent to surface rights holders before the work started or proof that you own the surface rights. 
  • If the work was performed on leases or patents, submit an up-to-date parcel abstract(s) (PIN(s)). Information on patents is available through the Land Registry Office(s).
  • If you are submitting costs for assessment credits related to georeferencing of your claims, you must file a technical report.  You can find out how to complete a technical report in the guide Georeferencing Standards for Unpatented Mining Claims.
  • If you are claiming Assessment Credits for Aboriginal Consultation Costs, you must submit an Aboriginal Consultation Costs Report form.  You can find out more about this in the policy Assessment Work Credits-Eligible Expenses related to Consultation with Aboriginal Communities.

If you wish to submit Payment-in-Lieu of Assessment Work, you must file an Application for Payment-in-Lieu of Assessment Work.  (form # 0319E)

Requirements for the filing of the Technical Report(s) and Map(s) for Assessment Work Credit

(Sections 9 to 19 of Ontario Regulation 6/96)

The requirements for the technical report(s) and maps submitted for Assessment Credit are described in Section 9 to Section 19 of the Assessment Work Regulation (Ontario Regulation 6\96.)

Viewing Previous Assessment Work

Assessment files are a source of geological information about a piece of land. They contain a historical record of mining and exploration work in Ontario. Assessment work collected by the Provincial Recording Office can be viewed using GeologyOntario.


For more information about assessment work requirements and filing assessment work, contact a Geoscience Assessor in the Provincial Recording Office.