Hypothetical question. I am looking to see if I will have to delay purchases to increase my deductions next year, or if I should wait until January to make those purchases and deduct them from my 2020 tax year.
NO
you cannot do that. You can only enter the state and local taxes for the tax year in which they were paid, and you are subject to the $10,000 SALT limit for all of your state, local, and sales taxes paid in that tax year. If you exceeded the $10,000 limit for your 2018 tax return, that is just the way it worked under the new tax law. You cannot save up the deduction and take it the following year.You can only deduct them the year you actually paid them, no matter what year they are for. So they would go on your 2018 return.
NO
you cannot do that. You can only enter the state and local taxes for the tax year in which they were paid, and you are subject to the $10,000 SALT limit for all of your state, local, and sales taxes paid in that tax year. If you exceeded the $10,000 limit for your 2018 tax return, that is just the way it worked under the new tax law. You cannot save up the deduction and take it the following year.