Missed Something on Your Tax Return? No Problem

PERSONAL TAX ADJUSTMENT

Recover missed refunds, correct errors, and update your CRA record easily for both residents and non-residents of Canada.

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What you need to know about adjusting your personal taxes

Adjust your taxes, receive what you deserve

Even after filing your tax return, mistakes and omissions can happen, and when they do, correcting them quickly and accurately is essential. A Personal Tax Adjustment ensures your return is accurate and that you receive every dollar you’re entitled to from the Canada Revenue Agency (CRA).

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Forgotten slip? No problem

If you’ve already filed your personal income tax return but later discover a missing T-slip, forgotten expense, or incorrect figure, you can file a T1 Adjustment Request (T1-ADJ) to fix it. This process allows the CRA to review and correct your previously filed return so your refund and tax record are accurate.

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Adjustments for non-residents

Non-residents of Canada often face unique tax challenges, especially when income is earned from Canadian sources such as employment, investments, or rental properties. Ensuring that your tax adjustment correctly reflects your non-resident status is essential to avoid penalties, double taxation, or missed refunds.

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Never pay more than you need to

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Share information about your self-employment, freelance, or rental income, and every required tax form is added for you.

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Whether you’re living in Canada or abroad, all available deductions are identified to help increase your tax savings.

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Enjoy peace of mind knowing your return is accurate, compliant, and optimized for the highest possible refund.

Why choose C.A.T.S for your personal tax adjustment?

Maximum Refund Guarantee

We search for every eligible deduction and credit to maximize your return.

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Specialists in Non-Resident Tax

We understand the complexities of cross-border income, residency changes, and foreign asset reporting.

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Completely Done-For-You Process

Send us the required documents and let our team of tax professionals handle the rest.

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Why Our Clients Love Us

  • "My Go-To for Years"

    C.A.T.S Accounting have been my go to tax consultants for years. Great service, very attentive and always on the mark. I highly recommend them.

    Amr A.

  • "Eliminated My Anxiety About Taxes"

    There are not words grand enough to express how much I enjoy working with [Tax Professional Name] and his fantastic team or how they have cleared the cobwebs from my mind thus reducing the anxiety associated with taxes. I am so blessed to have an accounting group to trust and console with at unexpected times. Thank you for your care and attention!

    Kiki N.

  • "Made My Taxes Less Painful"

    Excellent work. Your knowledge and guidance helped my tax issue to be less painful. THANK YOU!!

    Melia T.

  • "They Have Taken This Huge Tax Burden Off My List"

    As a busy real estate broker, my book keeping and tax submission has always been a worry for me. I started using Canada Accounting and Tax Services last year, and they have taken that huge burden off my list. [Tax Professional Name] and his team have managed to organize my books and streamline my tax submission. I highly recommend their services.

    Michael A.

  • "Exceptional Customer Care and Commitment"

    I would like to thank C.A.T.S Accounting office for their professionalism and sincere dedication in providing their accounting tax services to me throughout the past years. I’ve had a consistently and very positive experience with the office that continues to date. [Tax Professional Name] and his team go always extra mile to make sure everything is done properly, using all the tools and knowledge at their disposal. It is rare to encounter such a high standard of care and commitment. I wish them all the best and to many more successful years ahead.
    Thank you again🙏🏻

    Sherine B.

  • "Couldn't Recommend Them Enough"

    I have been going to CATS accounting for over 10 years now. I have never been disappointed and have never had any mistakes on my files. All the accountants are thorough, professional and very adept at what they do.

    Nadia W.

  • "Never Pay More Taxes Than Needed"

    C.A.T.S handles my personal and business accounting , excellent service , they do their best to ensure that you are not paying more than what you have to

    Ziyad M.

  • "Corrected Mistakes On My Previous Years' Taxes"

    Years ago, when a student, I had made a mistake on my taxes (doing it on paper, not using software). OSAP was not going to provide funding for my second undergraduate degree until my taxes were corrected. C.A.T.S. Accounting corrected the mistake and verified the previous few years of taxes. I have been using C.A.T.S accounting ever since

    Sheldon M.

  • "Exceptional Dedication to Client Service"

    I've been working with [Tax Professional Name] and his team at C.A.T.S Accounting for both my business and personal accounting needs since 2013 and I highly recommend their services.

    What distinguishes C.A.T.S Accounting is not only their comprehensive knowledge of accounting but also their exceptional dedication to client service. They are consistently available for queries, insights, and support, guiding me through every financial decision with ease. Their detail-oriented and proactive approach ensured a smooth and worry-free accounting process.

    Rami K.

  • "Impressed With Their Professionalism"

    Used CATS for the first time. I was very impressed with their professional method of getting taxes done. I highly recommend them

    Moez W.

Frequently asked questions

  • A T1 Adjustment Request, also known as a T1-ADJ, is a formal request to the Canada Revenue Agency (CRA) to correct or update information on a previously filed personal income tax return. It allows you to fix mistakes, add missing tax slips, or claim deductions and credits you forgot to include.

  • A tax adjustment should be filed as soon as you notice an error or omission on your return. Common reasons include missing a T4 or T5 slip, forgetting to claim tuition or medical expenses, or reporting the wrong income or contribution amounts. Filing early helps avoid delays and ensures you receive any extra refund owed to you.

  • You can request a tax adjustment for any of the previous 10 tax years. For example, in 2025, you can adjust returns filed as far back as 2015. The sooner you submit the correction, the faster the CRA can process it and issue any additional refund.

  • Once the CRA reviews your request, they’ll issue a Notice of Reassessment outlining the changes made and any additional refund or balance owing. You can track your adjustment status through CRA My Account or by contacting the CRA directly.

  • If you receive new or amended slips (like a revised T4 or T5) after filing, you should file a T1 Adjustment as soon as possible. Submitting the corrected information ensures your tax record is accurate and prevents future CRA issues or audits.

  • Yes. Non-residents who earn income from Canadian sources such as rental income, pensions, or investments can file a tax adjustment if their original return included errors or missed deductions. It’s important to indicate non-resident status correctly so the CRA applies the right tax treaties and rates.

  • No, filing a T1 Adjustment only changes the specific year being corrected. However, if the adjustment affects carryforward amounts (like tuition credits or capital losses), those changes may carry over and impact future returns automatically.

  • Yes. You can request adjustments for multiple tax years by filing a separate T1 Adjustment Request for each year. Each request must include the correct documentation for that specific year.

  • Yes. The CRA allows individuals to file or adjust returns for up to 10 previous years. This can be done if income was missed, a deduction was forgotten, or new information becomes available. Filing or adjusting past returns may result in additional refunds or reduced balances owing.

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