If you have more than one T4, then each T4 you enter should add to your income, that’s how it works.
If you only have one T4, you only need to enter it once. If you used the Auto-Fill my return service, make sure that you are not adding a slip that Auto-Fill has already entered for you. If you are preparing your return with a spouse, make sure that you are not accidentally entering their T4 under your name.
