wowsers said:I strongly advise you not to follow the advice you have been given to get a standard rental agreement, fill it in, backdate it and use it as proof that you were renting the property from parents. That would be a fraudulent misrepresentation which could destroy your chances of obtaining PR for ever. You do not need a tenancy agreement to prove the cohabitation at the parents' property: any proof that you were living there together will do. Get a letter from the parents for example setting out the facts. That is better than nothing and certainly better than misrepresenting the facts.
If they actually lived there on the dates they claim, it's not misrepresenting anything. There doesn't even have to be a date on when the rental agreement was physically signed... just what the dates of residency are.