auto depreciation

[pats1040]

client purchased light truck Dec 30 2019. uses it primarily for business. self employed. depreciation does not carry forward to his 2020 return.  after reviewing all, i realize a mistake was made on his 2019 return, where all info was entered, but the standard car allowance was used. so, I'm wondering if I can or should amend his 2019 return to show the depreciation, or is there any way i can allocate the depreciation to 2020? 

[dkh]

First question I have is how much is this truck actually used for business - you say "uses it primarily for business".      Doe "standard car allowance" mean  depreciation was "subject to auto limitations" or standard mileage allowance was used ?           

[qbteachmt]

"i realize a mistake was made on his 2019 return"

Just how much Business Use did he report specific to 2019, for one date?

https://www.irs.gov/taxtopics/tc510

"To use the standard mileage rate for a car you own, you must choose to use it in the first year the car is available for use in your business. Then, in later years, you can choose to use the standard mileage rate or actual expenses."

https://turbotax.intuit.com/tax-tips/self-employment-taxes/standard-mileage-vs-actual-expenses-getti...