If you have opened a "My Account" with Canada Revenue, I believe that you can go on and make changes to your return before thay have begun to process it. You will have to have the figures for the coupled returns to plug into the individual returns. You may have to pay for the two coupled returns in order to save a copy for later corrections. Make sure there is enough of a difference to make it worth while.
Another method is to wait until the returns are processed and then do a T1 adjustment request to correct any errors. CRA may correct it themselves depending on the change.
Make sure you know exactly what is causing the difference between the two sets of forms, to determine which set really is the correct one.
