Do I enter anything under income for my business if we didn't earn any money in 2021? Should I leave income blank or fill it in zeros everywhere?

[dewz]

This is a great question - should you enter in zeros (0) or leave it blank?

If you enter in zeros, that will imply that you are also entering non-zeros on the same form/schedule/document. However, if the entire form and fields will be zero, it is best to leave it blank and not use it.

In summary, if the zeros will have offsets that are greater than 1, enter zeros. If the entire form will be blank, don't enter it/create it or it will appear that it is incomplete.

[AnnetteB6]

If you are claiming business expenses, but no income, then it would be good to enter a zero in at least one category of income such as 'cash' payments.

That zero would indicate that you did not unintentionally forget to report your income.  

If you did not operate your business in 2021 and did not have any expenses for the year either, then you would not need to file the Schedule C unless there are assets you are depreciating for your business.  If you have stopped operating the business in 2021, then you should indicate that on Schedule C and file it for the final time even if income and expenses are all zero.

@avengerbailbonds