This is how I tackle depreciating the assets.
Here we have two “levels” of depreciation. Firstly, depreciation for accounting purposes, and secondly depreciation for taxation purposes.
For accounting purposes, one is supposed to take a balanced view as tho the useful working life of the asset and depreciate it accordingly. How you do this is largely up to you, but you are required to be reasonable and sensible.
For taxation purposes, the taxation authorities prescribe the allowable rates of depreciation for certain types or classes of assets.
So, what you end up with is two registers of assets running side-by-side depreciating the assets at different rates. The value of the difference between the two registers is known as “deferred tax”, and is stated in the published accounts of the business.
Now, this all sounds a tad complicated and many people simply keep their own register for accounting purposes only, and have their accountant apply and re-state the taxation depreciation values when submitting the accounts on their behalf to the taxation authorities. However, arithmetically, what is happening is quite simple. (always worth remembering that at the end of the day, this sort of thing is just arithmetic).
Firstly, the tax authorities specify prescribe “pools” for certain classes of assets. For example Commercial Vehicles in one group, Plant & Equipment in one group, Office Equipment in one group and so forth.
So, following the authorities lead, I create a spread-sheet for each class or pool of asset and set the depreciation rate desired, and then just post the summary total of each pool to Manager using the journal facility.
I find that once you have got this set-up, it’s quite easy to keep on top of it, and once a month, I do my journals from a pre-prepared schedule as it typically For me at least) proves to be quite repetitive in nature.
Here’s a screen-shot of a part of an old register that I use, but it illustrates what I am trying to describe:-
Obviously, the detail of how you handle this will vary in different jurisdictions around the world, but the principle should hold good.