Deductions & credits

 I understand how to allocate percentage use for the cell phone bill

 

My question is concerning the cost of the phone. Rather than paying for the whole phone upfront my provider is having me pay $40 monthly until the phone is paid off. Do I still deduct the whole cost of the phone up front (subject to percentage business use) as if i paid for the whole thing this year.

 

When i buy a laptop for my business I pay for the whole thing and take a section 179 deduction for the percent business use