Yes it matters if they took out FICA (SS & Medicare). Did you get a 1099Misc or a W2 for it?
Was that your only income? If you were an employee and got a W2 you don't have to file a return. If you got a 1099Misc or no form you have to file a return for only $400 or more and pay the self employment tax on it.
Self Employment tax (Scheduled SE) is automatically generated if a person has $400 or more of net profit from self-employment. You pay 15.3% SE tax on 92.35% of your Net Profit greater than $400. The 15.3% self employed SE Tax is to pay both the employer part and employee part of Social Security and Medicare. So you get social security credit for it when you retire. You do get to take off the 50% ER portion of the SE tax as an adjustment on 1040 Schedule 1 line 27. The SE tax is already included in your tax due or reduced your refund. It is on the 1040 Schedule 4 line 57 which goes to 1040 line 14. The SE tax is in addition to your regular income tax on the net profit.
Do you need to amend or file a 2017 return?
Thanks for the explanation this helped a lot. This was for my brother. Based on your explanation, my brother will need to file a 2017 return. This related to his student loan application. But will inform him to file.