It’s happened to your dad, your childhood best friend, your boss, and — if you’re reading this post — it’s probably happened to you. You’ve gathered all your documents, completed your tax return, filed it through NETFILE, and are feeling pretty good about being done. But then you receive another slip, find a missing receipt, discover a typo, or realize you need to make a change.
First, don’t panic — you can change your return. While you can’t resubmit your return through NETFILE, making a change isn’t hard. This article walks you through what you can adjust, the three ways to request a change, how far back you can go, and how long it takes.
You can change your return once it’s been assessed. If you filed through NETFILE, this usually happens within two weeks — the Canada Revenue Agency’s (CRA) published service standard for returns filed online. If you didn’t use NETFILE, or if you invest in tax shelters, this can take longer.
Using CRA My Account, you can click the “Tax Return” tab to see whether your return has been assessed.
What you can and can't change
You can change amounts you reported and add information you missed. You can’t use a change request to update personal details, apply for benefits, or revise certain elections — those go through separate CRA channels.
Common changes the CRA will accept include:
Unreported income — a T4 slip or tips you left off.
Missed deductions or credits — medical or childcare costs, for example.
Late slips — an RRSP contribution receipt that arrived after you filed.
You can’t use a change request to:
apply for benefits or credits;
make or revise an election;
move a refund to another CRA account;
update personal details like your address, marital status, name, or direct deposit information.
How to change your tax return
Using CRA My Account
You can change your return through most tax software, or online through CRA My Account. Log in and click the blue Change my return link in the Tax Returns section.
Select the year you want to change. A page like this will appear:
Use the search box to find the line numbers that have changed on your return. Enter any amounts that have changed (several fields won’t accept decimal places, only enter decimals, if the field you are changing shows decimals in CRA My Account).
Make all your changes before clicking Review and Submit Changes. The CRA saves your changes as you go, though there’s no save button. When you’re happy with your changes, click Submit.
When you submit, the CRA may show errors or warnings. Errors stop you until you provide more information, while warnings flag details you may want to add.
After submitting, you may have an amount owing. For larger amounts, you may be able to arrange to pay in installments.
You can pay the CRA through your bank, much like paying a bill: add the CRA as a payee and use your Social Insurance Number (SIN) as the account number. Confirm your changes and payment in CRA My Account.
Using ReFILE and certified tax software
If you filed electronically, ReFILE is often the quickest option since all of your information is already in the workflow. ReFILE is a secure CRA service built into most certified tax software that lets you resubmit a corrected federal return electronically — no paper or postage required.
You can use ReFILE once your return has been assessed and only if your original return was filed electronically. It’s well suited to common fixes like a late slip, income you forgot to report, or a deduction or credit you missed. But it's worth noting that ReFILE only adjusts the figures on your return — it can't update personal details such as your marital status, address, direct deposit, or email. You update those separately in the personal information section of your CRA account (see the CRA's "Update your personal information" page).
On paper (T1 Adjustment Request)
If you can’t use ReFILE or CRA Change my return service, you can file a paper T1 Adjustment Request. For each change, list the line number, the amount you originally reported, the amount of the change, and the revised amount, plus a short note on why you’re requesting the change. Mail it, along with any supporting slips or documents listed on the form, to your tax centre (find the address on page 2 of the form).
How far back you can change a return
You don’t have to catch a mistake right away. If you use certified tax software, ReFILE lets you adjust the current year and the 3 years before it. If you use the CRA Change my return service or file a paper T1 Adjustment Request, you can go back up to 10 years.
You can’t submit a new change while an earlier request is still being processed. Wait to hear back from the CRA before sending another for the same year.
How long a change takes and what happens next
How long your change takes depends on how you send it. Online requests through your CRA account or certified software are usually processed within two weeks. A paper T1 Adjustment Request can take up to ten weeks from the day the CRA receives it. Some of the more complex requests take longer — up to 39 weeks — for example those covering several years, going back beyond the normal three-year reassessment period, or where the CRA asks you for supporting documents.
Once your request is processed, the CRA sends a notice of reassessment showing what changed. There are three possible outcomes:
the CRA makes all your changes;
the CRA makes some of your changes;
the CRA makes none of them and explains why.
If the change lowers your tax, your refund is sent once the request is processed. If it raises your tax, you’ll have an amount owing.
