As of October 24, 2017, the maximum age of dependency has increased from 19 to 22. This also means that the length of the undertaking (the length of time you are financially responsible for the person you sponsor) for dependent children has changed:
- If your dependent child is less than 22 years of age when they become a permanent resident, you are financially responsible for them for 10 years after they become a permanent resident, or until they turn 25 years old, whichever comes first.
- If your dependent child is 22 years of age or older when they become a permanent resident, you are financially responsible for them for three years after they become a permanent resident.
Also, the government of Canada has implemented some transitional policies for this change. You can use this flow chart to determine if you eligible:
https://www.canada.ca/en/immigration-refugees-citizenship/news/2017/10/determining_who_iseligibleasadependantunderthepublicpolicyonthea.html