The answer to your question is that you will take into account (for
purposes of a potential tax deduction) those amounts that were paid by you during the January 1 to December 31 calendar year. In the case of a credit card, when you make a "charge" on credit car, the merchant, or in this case the government, is paid immediately by the credit card issuer. Thus, you can (and should) consider an expense as being paid when the credit card charge is initiated, not when you actually pay on your credit card monthly statement. So, in your case specifically, a charge made in December 2016 is an item for your 2016 tax return (even where you pay the credit card bill in January, 2017,or later)
That said, there is something else (highly relevant to your original question) that we should also discuss here.
There is no direct tax deduction for
vehicle registration fees on a personal tax return. Although if you live
in a state that imposes an excise tax amount, based in some way on the market value of the vehicle, and that is part of the
registration process, then the excise tax can be deducted, but not the whole
amount of the cost of registration.
The legal reasoning is as
follows. The IRS only allows that portion of a state registration fee
that is based on the value of the vehicle to be included toward your
other itemized deductions. Any flat fee portion doesn't count. This
is why there are some 20+ states whose residents can potentially benefit from
the deduction; but the remainder cannot: their states do not charge
vehicle registration fees by value, and instead charge flat fees only.
There is a list of these
qualifying states built-into the TurboTax software. A graphical image of
this chart of states is also shown in the screen-capture image at the
bottom of this answer (simply click to enlarge).
If your state is on the list,
then you can enter the vehicle excise tax amount in TurboTax. To do so,
you will want to have your tax return open and locate the Search / Find
box on your screen. Next, type in the exact search string "vehicle
registration fees" and then click on the Jump To link that
should appear beneath. This will take you to the appropriate data entry
place in the program.
Thank you for asking this question.
