Hello, thanks for reaching out
If you have claimed Capital Cost Allowance (CCA) in the past on your vehicle used for Business or Employment, you will have a number left at the end of the year known as Undepreciated Capital Cost or UCC.
If this is your first time claiming CCA on that vehicle, you will not have a UCC amount. UCC is the balance of the capital cost left for further depreciation at any given time.
For example, if you claimed the full 30% CCA on a $10,000 vehicle last year, your UCC would be $7,000
( $10,000 - $3,000 = $7,000 UCC)
https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/deductions-credits-expenses/line-22900-other-employment-expenses/capital-cost-allowance.html
Hope this helps!