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How to Appeal a CRA Reassessment Canada 2026

Updated

Understanding Reassessments

If you are dealing with a reassessment in real time, align this process with how to appeal a CRA decision and how to dispute a CRA assessment or reassessment. Confirm what triggered the change before verifying the numbers on your Notice of Assessment.

Types of CRA Adjustments

TypeWhat It Means
ReassessmentCRA changed your return
AdjustmentYou requested a change
Audit assessmentResult of review/audit
Arbitrary assessmentCRA filed for you

Common Reassessment Reasons

ReasonExample
Disallowed deductionRRSP over-contribution
Income additionUnreported T4/T5
Credits deniedDTC not approved
Audit adjustmentBusiness expenses disallowed
Error correctionMath mistakes

The Appeal Process

Three Levels of Dispute

LevelTimelineCost
1. Notice of Objection90 days to fileFree
2. Tax Court of Canada90 days after CRA decisionVaries
3. Federal Court of Appeal30 days after Tax CourtHigher

Level 1: Notice of Objection

Deadline

SituationDeadline
Standard90 days from reassessment date
ExtensionUp to 1 year from deadline
Extension requirementsReasonable grounds, file within 1 year

How to File

MethodDetails
OnlineCRA My Account → Register a dispute
MailForm T400A or letter to Tax Centre
FaxTo Appeals Intake Centre
In personAt tax services office

What to Include

ElementDetails
Tax year(s)Which years disputed
IssuesWhat CRA got wrong
FactsYour version of events
Legal groundsTax law supporting you
DocumentsReceipts, statements, etc.
Relief requestedWhat you want

Sample Objection Letter

[Your Name]
[Address]
[SIN]
[Date]

CRA Appeals Division
[Address]

Re: Notice of Objection - [Tax Year]

I am filing this objection to the Notice of Reassessment 
dated [date] for the [year] taxation year.

Issue: [Describe what CRA changed]

Facts: [Explain what actually happened]

Position: [Why you disagree with CRA]

Supporting Documents: [List attachments]

Relief Requested: [What you want - reversal, adjustment]

Sincerely,
[Your name]

What Happens After Filing

CRA Appeals Process

StageTimeline
Acknowledgement2-4 weeks
Assigned to officer1-6 months
Review3-12+ months
DecisionNotice of Confirmation or reassessment

Possible Outcomes

OutcomeMeaning
Allowed in fullYou win completely
Allowed in partPartial victory
ConfirmedCRA stands by reassessment
VariedDifferent adjustment

Level 2: Tax Court of Canada

When to Go to Court

SituationConsider Court
CRA confirmed objectionNext step
CRA took 90+ daysCan appeal directly
Strong caseWorth pursuing
Significant amountJustifies cost

Time Limit

TriggerDeadline
Notice of Confirmation90 days to appeal
CRA didn’t respond (90+ days)Anytime after

Court Procedures

ProcedureAmountDetails
InformalUnder $25,000/yearSimpler, no lawyers needed
GeneralOver $25,000/yearFormal, usually need lawyer

Informal Procedure

FeatureDetails
Cost$100 filing fee
RepresentationSelf, accountant, or lawyer
RulesSimplified
EvidenceMore flexible
TimeFaster resolution

Collections During Dispute

Requesting Collections Hold

RuleDetails
Automatic holdCollections paused during objection
Court appealMay need to request hold
InterestContinues to accrue
SecurityCRA may require

Paying While Disputing

OptionConsideration
Pay in fullRefunded if you win, with interest
Pay nothingCollections held but interest accrues
Pay partialReduce interest accumulation

Tips for Success

Building Your Case

TipWhy
Gather all documentsProve your position
Be detailedExplain clearly
Cite tax lawStrengthen argument
Organize chronologicallyEasy to follow
Get professional helpIf complex

Common Mistakes

MistakeImpact
Missing deadlineLose appeal right
Vague objectionWeak case
No documentsCan’t prove claims
Emotional languageUnprofessional
Wrong form/processDelays

When to Get Help

Consider a Professional

SituationRecommended
Large amountsYes
Complex issuesYes
Business mattersYes
Simple errorsMaybe self-file
Audit-relatedYes

Who Can Help

ProfessionalBest For
Accountant (CPA)Tax calculations, basic disputes
Tax lawyerComplex legal issues, court
Tax specialistSpecific expertise

Cost Considerations

ServiceTypical Cost
Accountant review$200-$1,000
Objection assistance$500-$3,000
Tax Court (informal)$2,000-$10,000+
Tax Court (general)$10,000-$50,000+

Taxpayer Bill of Rights

Your Rights

RightProtection
Be treated professionallyRespect and courtesy
PrivacyInformation confidential
Complete informationKnow your obligations
Fair applicationConsistent interpretation
AppealFormal dispute mechanism

Taxpayer Ombudsman

When to ContactIssue
Service complaintsNot audit disputes
Process delaysUnresponsive CRA
Conduct issuesCRA behavior