MyCRA is CRA’s mobile app that can be very convenient for individual taxpayers to use. From this mobile app, you can access key portions of your tax information and you can also pay for your balance owing.

So how do you get started? To get started, you need a CRA user ID and password. If you have not registered for one, you will need to register on the login page.

Note that you will be asked personal tax information when registering for the app. So be ready with your social insurance number, birth date, your current postal code and the amount you entered on one of your income tax and benefit returns. Have a copy of your returns on hand when doing the registration.

You will also be asked to create security questions and answers during the registration process.

Once you have completed your registration, the CRA will issue a security code. You will need this security code to access MyCRA and use all of its features. Once you have your security code (sent by mail), enter the code when you log in so you can get started on using MyCRA.

Another alternative to signing in with a CRA user ID and password is logging in with a Sign-in Partner. This option will let you log in with a user ID and password that you may already have, such as for your online banking.

Source: https://www.canada.ca/en/revenue-agency.html