Are you sure, refiling our taxes as common law is for sure required? where is this mentioned, and would taxes for 2020 only suffice, or does it have to be for all past three years? and should we in that case, have one joint CRA account as well for sure?You need to be filing your taxes as common law if you are in fact common law partners. This is one of the pieces of evidence that IRCC will consider to confirm your status and you must include your NOAs in the parent sponsorship application. You will both need to refile your tax returns as common law.
Yes - you need to include him in the LICO calculation which will bring the total to 4 people.