Depreciation in any year that must be accounted for is the amount that is "allowed or allowable". It is maintained in the accumulated depreciation account. It is a form of a reserve. Depreciation process may actually properly be called "cost recovery".
Hence, there is never any unaccounted depreciation. (I can't be sure of what you may even mean, and suspect you don't really have any idea yourself and are just making up terms!)
There is of course frequently, a remaining book value to the property, undepreciated either because it required a resideual value be set up or it has not been owned for it's depreciable life. That is the basis used upon disposal or sale.
Some things have very long depreciable lifes so there is still more to be taken, many things....land especially...does not depreciate at all and any cost is recovered on disposal.
Depreciation
Renting the car for a specific period of time and paying for its depreciation.
Renting the car for a specific period of time and paying for its depreciation.
A calendar month is the smallest unit of time used to calculate depreciation. A plant asset may be placed in service at a date other than the first day of a fiscal period. In such cases, depreciation expense is calculated to the nearest first of a month. To calculate depreciation expense for part of a year, the annual depreciation expense is divided by 12 to determine depreciation expense for a month. The monthly depreciation is then multiplied by the number of months the plant asset was used that year.
The answer to this question depends on the value of the depreciable assets the company has, the useful lives of the assets, and the depreciation methods used. When a firm owns many depreciable assets, depreciation expense will be higher. The longer the useful lives of the assets, the less the depreciation expense will be per period because the expense is being allocated over a longer period of time. The depreciation method also has a huge impact. If the straight-line method is used, then the expense will be constant each period. If another method such as double-declining balance is used, higher depreciation will occur during the beginning of the life of the asset. All of these factors affect the balance of the depreciation expense account.
The straight-line depreciation method allocates an equal amount of depreciation expense over the useful life of an asset, resulting in a constant annual depreciation expense. In contrast, the reducing balance method accelerates depreciation expense by applying a fixed percentage to the remaining book value of the asset each year, leading to higher depreciation charges in the early years of the asset's life.
Value of the property at current period of time i.e. not considering depreciation while valuation of the asset.
In order to increase accumulated depreciation, you allow time to pass. It will depreciate more over time.
Accumulated depreciation is the amount of a long-term's asset's cost that has been allocated to depreciation since the time the asset was acquired.
External depreciation is not based on the passage of time. A property depreciates due to external forces that can not be controlled by the owner.
Depreciating assets over time causes the Accumulated Depreciation to go up with a credit entry. The debit is to depreciation expense.
That is entirely up to the user and how they utilise the 'phone.