When you file your taxes, after the end of the year.
The deductions for your retirement plan (if applicable) and 1/2 of self-employment tax go in the adjustments section on the front of Form 1040. The deductions for expenses go on Schedule C or C-EZ.
You track your expenses related to the self-employment and both your income and expenses are reported on Schedule C of the 1040 that you file next year.
When you file your tax return, as expenses on your Schedule C.
You use Schedule C with Form 1040, assuming you didn't incorporate.
self employment is reported on Sch C, the income and the expenses rela ted to it are claimed on that form, you can see one at www.irs.gov
As part of your annual tax return
The are the expenses on Schedule C