How do I dispute a CRA reassessment?

File a Notice of Objection within 90 days of the reassessment date. You can file online through My Account, by mail, or by fax. Include your reasons for disputing and supporting documents.

What is the deadline to appeal a CRA decision?

You have 90 days from the date on your Notice of Reassessment to file a Notice of Objection. If you miss this, you can apply for an extension up to one year from the deadline.

Can I appeal if I already paid the reassessment?

Yes, paying does not waive your appeal rights. If your objection succeeds, CRA will refund the overpayment with interest. You can also request collection be held during the appeal.

How to Appeal a CRA Reassessment Canada 2026

Understanding Reassessments

Types of CRA Adjustments

Type	What It Means
Reassessment	CRA changed your return
Adjustment	You requested a change
Audit assessment	Result of review/audit
Arbitrary assessment	CRA filed for you

Common Reassessment Reasons

Reason	Example
Disallowed deduction	RRSP over-contribution
Income addition	Unreported T4/T5
Credits denied	DTC not approved
Audit adjustment	Business expenses disallowed
Error correction	Math mistakes

The Appeal Process

Three Levels of Dispute

Level	Timeline	Cost
1. Notice of Objection	90 days to file	Free
2. Tax Court of Canada	90 days after CRA decision	Varies
3. Federal Court of Appeal	30 days after Tax Court	Higher

Level 1: Notice of Objection

Deadline

Situation	Deadline
Standard	90 days from reassessment date
Extension	Up to 1 year from deadline
Extension requirements	Reasonable grounds, file within 1 year

How to File

Method	Details
Online	CRA My Account → Register a dispute
Mail	Form T400A or letter to Tax Centre
Fax	To Appeals Intake Centre
In person	At tax services office

What to Include

Element	Details
Tax year(s)	Which years disputed
Issues	What CRA got wrong
Facts	Your version of events
Legal grounds	Tax law supporting you
Documents	Receipts, statements, etc.
Relief requested	What 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

Stage	Timeline
Acknowledgement	2-4 weeks
Assigned to officer	1-6 months
Review	3-12+ months
Decision	Notice of Confirmation or reassessment

Possible Outcomes

Outcome	Meaning
Allowed in full	You win completely
Allowed in part	Partial victory
Confirmed	CRA stands by reassessment
Varied	Different adjustment

Level 2: Tax Court of Canada

When to Go to Court

Situation	Consider Court
CRA confirmed objection	Next step
CRA took 90+ days	Can appeal directly
Strong case	Worth pursuing
Significant amount	Justifies cost

Time Limit

Trigger	Deadline
Notice of Confirmation	90 days to appeal
CRA didn’t respond (90+ days)	Anytime after

Court Procedures

Procedure	Amount	Details
Informal	Under $25,000/year	Simpler, no lawyers needed
General	Over $25,000/year	Formal, usually need lawyer

Informal Procedure

Feature	Details
Cost	$100 filing fee
Representation	Self, accountant, or lawyer
Rules	Simplified
Evidence	More flexible
Time	Faster resolution

Collections During Dispute

Requesting Collections Hold

Rule	Details
Automatic hold	Collections paused during objection
Court appeal	May need to request hold
Interest	Continues to accrue
Security	CRA may require

Paying While Disputing

Option	Consideration
Pay in full	Refunded if you win, with interest
Pay nothing	Collections held but interest accrues
Pay partial	Reduce interest accumulation

Tips for Success

Building Your Case

Tip	Why
Gather all documents	Prove your position
Be detailed	Explain clearly
Cite tax law	Strengthen argument
Organize chronologically	Easy to follow
Get professional help	If complex

Common Mistakes

Mistake	Impact
Missing deadline	Lose appeal right
Vague objection	Weak case
No documents	Can’t prove claims
Emotional language	Unprofessional
Wrong form/process	Delays

When to Get Help

Consider a Professional

Situation	Recommended
Large amounts	Yes
Complex issues	Yes
Business matters	Yes
Simple errors	Maybe self-file
Audit-related	Yes

Who Can Help

Professional	Best For
Accountant (CPA)	Tax calculations, basic disputes
Tax lawyer	Complex legal issues, court
Tax specialist	Specific expertise

Cost Considerations

Service	Typical 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

Right	Protection
Be treated professionally	Respect and courtesy
Privacy	Information confidential
Complete information	Know your obligations
Fair application	Consistent interpretation
Appeal	Formal dispute mechanism

Taxpayer Ombudsman

When to Contact	Issue
Service complaints	Not audit disputes
Process delays	Unresponsive CRA
Conduct issues	CRA behavior