When you make a mistake on your (already filed) tax return

May 3, 2023by Akmin

The vast majority of Canadians view completing and filing their annual tax return as an unwelcome chore, and generally breathe a sigh of relief when it’s done for another year. When things go entirely as planned and hoped, the taxpayer will have prepared a return that is complete and correct, and filed it on time, and the Canada Revenue Agency (CRA) will issue a Notice of Assessment indicating that the return is “assessed as filed”, meaning that the CRA agrees with the information filed and tax result obtained by the taxpayer. While that’s the outcome everyone is hoping for, it’s a result which can be derailed in any number of ways.

Over 94% of the returns which had been filed for the 2022 tax year by mid-April 2023 were filed through online filing methods (NETFILE or EFILE), meaning that they were prepared using tax return preparation software. The use of such software significantly reduces the chance of making a clerical or arithmetic error, like entering an amount on the wrong line or adding a column of figures incorrectly. However, no matter how good the software is, it can work only with the information that is provided to it. Sometimes taxpayers prepare and file a return, only to later receive a tax information slip that should have been included on that return. It’s also easy to make an inputting error when transposing figures from an information slip (for example, a T4 slip from one’s employer) into the software, such that $73,246 in income becomes $72,346. Whatever the cause, where the figures input are incorrect or information is missing, those errors or omissions will be reflected in the final (incorrect) result produced by the software.

In other cases, a receipt for something like a charitable donation may be overlooked when the taxpayer is completing the return, or may be received after the return has already been filed. Whatever the cause or reason for the error or omission in an already filed return, the question which immediately arises is how to make things right. And, no matter what the reason for the error or omission, the course of action to be followed by the taxpayer is the same.

The first impulse of many taxpayers when a mistake or omission is discovered is to file another return, in which the complete and correct information is provided, but that’s not the right answer. There are, however, several ways in which a mistake or omission on an already filed tax return can be corrected, including online options.

As well the right response (although it seems counterintuitive) is, at least initially, to do nothing. The taxpayer must wait until the CRA has issued a Notice of Assessment with respect to the incorrect return already filed, for the very good reason that the return as filed isn’t in the CRA’s system until then. Once the Notice of Assessment is issued, however, there are three options available to the taxpayer to make the necessary correction.

Taxpayers who are registered for the CRA’s online service “My Account” can avail themselves of the Agency’s online “Change My Return” feature at Change my return: online adjustments for income tax and benefits returns – Canada.ca. The process is quite straightforward – using a drop-down menu, the taxpayer chooses the tax year for which he or she wants to make a change on the return and can then search for the line number on which the change is needed.  A “new amount” box will appear, into which the correct amount is input. A summary page will then show the old and new numbers and, if the taxpayer is satisfied that the information is correct, he or she clicks on “Submit Changes”. A confirmation number for the changes made is then provided. The CRA will then process the information and issue a new Notice of Assessment which reflects the changes made.

Taxpayers who are not registered for My Account but who have filed their tax return using one of the Agency’s electronic filing services (whether NETFILE or EFILE) can make a correction on their return by using the Agency’s ReFILE service. Like the Change my Return feature, the ReFILE service (available at https://www.canada.ca/en/revenue-agency/services/e-services/e-services-businesses/refile-online-t1-adjustments-efile-service-providers.html) enables taxpayers to make corrections to an already filed return online, on the CRA website.

Essentially, taxpayers whose returns have been filed online (through NETFILE or EFILE) can make a correction using the same tax return preparation software that was used to prepare the return. Those taxpayers who used NETFILE to file their 2022 tax return can file an adjustment to a return filed for the 2019, 2020, 2021, and 2022 tax years. Where the return was filed using EFILE, the EFILE service provider can similarly file adjustments for returns filed for the 2019, 2020, 2021. or 2022 tax years.

There are limits to the ReFILE service. Regardless of who is using the service (i.e., the taxpayer or an EFILE service provider) the online system will accept a maximum of nine adjustments to a single return, and ReFILE cannot be used to make changes to personal information, like the taxpayer’s address or direct deposit details. There are also some types of tax matters which cannot be handled through ReFILE, like applying for a disability tax credit or child and family benefits.

While using the CRA’s online services, whether through ReFILE or Change my Return, is certainly the fastest way to make a correction on an already-filed return, taxpayers who don’t wish to use an online method do still have a paper option. The paper form to be used is Form T1-ADJ E (20), which can be found on the CRA website at T1-ADJ T1 Adjustment Request – Canada.ca. There is no limit to the number of changes or corrections which can be made using the T1-ADJ E (20) form.

A hard copy of a T1-ADJ(20) (or a letter) is filed by sending the completed document to the appropriate Tax Center, which is the one with which the tax return was originally filed. A listing of Tax Centres and their addresses can be found on the reverse of the TD-ADJ (20) form. As well, the taxpayer can go to https://www.canada.ca/en/revenue-agency/corporate/contact-information/tax-services-offices-tax-centres.html on the CRA website and select their location from the drop-down menu found there. The address for the correct Tax Centre will then be provided.

Where a taxpayer discovers an error or omission in a return already filed, the impulse is to correct that mistake as soon as possible. However, it’s important to remember that no matter which method is used to make the correction – ReFILE, My Account. or the filing of a T1-ADJ in hard copy – it’s necessary to wait until the Notice of Assessment for the return already filed is received.  Corrections to a return submitted prior to the time that return is assessed simply can’t be processed by the Agency.

Once the Notice of Assessment is received, and an adjustment request is made, it will take at least a few weeks, usually longer, before the CRA responds. The CRA generally aims to respond to online requests within two weeks and to paper-filed requests within eight weeks.

The information presented is only of a general nature, may omit many details and special rules, is current only as of its published date, and accordingly cannot be regarded as legal or tax advice. Please contact our office for more information on this subject and how it pertains to your specific tax or financial situation.