Claiming Leasehold Improvements from past years

A new client of mine shows TI’s on her balance sheet of $54,275 from 5 years ago. Her business has never shown the CCA on the T2125 because she hasn’t been in a positive income position. Can I set up the Asset this year and start? or do we need to go back and add to the year the improvements happened? thanks for any hints on this

I would set up the asset this year and start with a full year depreciation/amortization. Have your supporting documents available, but otherwise go for it.