IF one is required, it would be done as a separate tax file. IF you use the Online software, make sure you use an entirely different account from yours...any attempt to use your own account would destroy one of the tax files, depending on whose was done first,
1) IF he gets a W-2 for that work, and Federal or state taxes were withheld, then a tax return "can" be filed for him to get any withholding taxes back. SS and Medicare taxes are not refunded. But do it together with him...he needs to see how it is done. If no Federal or state income taxes were withheld, then his income is low enough that a federal tax return would not be required, but make sure you add in any bank interest to his income too. States vary though. I don't think any would require a tax return at that income level, but I'm not sure, ..check your state's online tax page to see what the minimum income would be.
2) if the work done was for cash, or a 1099-MISC is issued for his work, then a tax return would be required to be filed for him. He would have to pay Medicare and SS taxes on the gains from that "cash" work. It is considered Self-Employment income.
3) I recommend preparing and filing your own taxes first. That prevents any problems with your own filing should you accidentally set his dependency status wrong on his tax file.
4) For #1 above, his tax return should be able to use the Online "Free" version...unless he also has a brokerage account that has stock bond sales for 2019. For #2 above, his tax return would require the use of the Online SE version, which is not free.
(Many of us usually recommend the use of the Desktop/download versions of TTX for people who have multiple tax returns to file. Mostly because you can work on multiple files, and create test files too, and would cover both situations above. Deluxe or higher should be used, but be careful when buying any Deluxe, since there are some versions that don't include a free state download (If bought direct from TTX, it always includes one state software set). Even if the state download is included, the E-filing for the state is an added $25 (except NY)...but the state forms could be mail-filed for the cost of your paper and postage)
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
