Can you change methods?

No. Once you adopt one method of depreciation for a particular item, you cannot change to the other method for that item. For example, if you choose the prime cost method for all or some items becoming depreciable in a particular year, you must continue with that method for those items for as long as you own them. If you purchase similar items in later years, you must still choose which method of depreciation to apply to those items. An exception to this rule is when you have chosen the prime cost method and later decide to allocate the item to a common-rate pool. The diminishing value method is the only method allowed for calculating depreciation deductions for items allocated to a common-rate pool. See information on: common-rate pools.