When should my son start filing his own tax? Is there a age or earned wage criteria?

[rakumarji]

in 2020, he was full time student for 6 mths, worked fulltime 6 mths on W2 and earned approx $27k. Should he fill his own tax seperately or I may add him in my tax rerurn? What is recommended?

[SteamTrain]

You can never include his W-2 on your tax return.

There is a minimum $$ for filing, but he is waaaay over  ($12,400 income for a single person) .  So he must have his own tax return prepared and filed.

IF he was under age 24 at the end of 2020, (and was a full-time student at least one day in each of 5months) then you can still claim him as a dependent on your tax return, but he must indicate that he is being claimed as a dependent by someone else when he files his.    DO your own and file it before working on his to avoid complications.

IF using Online software, he must have his own separate account .......annnnnd  you should both work on it together. It is critical that he learns how it has to be done, and you may need to get more experience with the software yourself.