If you paid for the expense in 2018 then it has to be entered on your 2018 Schedule C if you are referring to self-employment expenses.
If you are referring to personal deductions reported on a Schedule A then you either report the personal deduction or not, it is up to you. However, if the deduction was paid for in 2018 it cannot be deducted on the Schedule A in 2019.
If you paid for the expense in 2018 then it has to be entered on your 2018 Schedule C if you are referring to self-employment expenses.
If you are referring to personal deductions reported on a Schedule A then you either report the personal deduction or not, it is up to you. However, if the deduction was paid for in 2018 it cannot be deducted on the Schedule A in 2019.
You can only claim a deduction in the year that you actually make the payment. Since it's already January 1, you don't have any flexibility to delay 2018 deductions. Anything you already paid in 2018 can only be deducted on your 2018 tax return. You can't just choose to wait and claim the deduction for 2019.
The only way to delay a deduction is to delay making the payment. For example, you could delay a deduction for contributions to charity by making the contribution in January instead of December. If you normally make a state estimated tax payment in December, you could delay it until January (before January 15). But other types of deductions, such as real estate tax or mortgage interest might not be as easy to delay. Your town or your mortgage lender might not be very understanding if you pay late, and they might charge a penalty or additional interest.
Thank you for your great answers! What if I already have more deductions that self employed income eliminating all taxable income even without adding my personal charity donations? Can deductions be rolled over to the following year?
Now are you are talking about self employment expenses vs personal deductions? They are separate. You have to enter all your schedule C self employment expenses. You can show a loss on schedule C. A loss on sch C will not roll over. Unless you have NOL, I don’t know how that works.
Yes, Self Employment. Ok. Does I get a check for a shown loss?
If you have a business loss it will subtract from all your other income so you will have less taxable income. You can only reduce your taxable income to zero. Then you won’t owe any income tax and no self employment tax. And you will get a refund of all your federal withholding and estimated payments you made.