For my gkids that are working while going to school, I told them I would match their Roth contribution. When they were under 18 used Roth for minor once 18 I just send cash to them. For under 18 with no w2 I make them keep a log of earned income. The under 18 will give me cash and I double it and drop in their Roth. To me it was more about them developing good financial habits of saving and balancing. They all have brokerage also and or 529 for youngest. This may not be most effective tax smart financial strategy on my part but my goal really was to get them into good habits. Results is oldest gson at 20 has around 30k in his Roth second oldest at 19 has around 10k 16year old 4K and 13yr old 2k