Every asset your business owns loses value the moment it's put to use. That's not a bad thing. It's an accounting fact, and how you record it affects your financial statements, your tax bill, and how accurately you understand what your organisation is actually worth. The problem is that "depreciation" isn't one calculation. It's a family of methods, and picking the wrong one (or doing the right one by hand in a spreadsheet that quietly drifts out of sync) causes real problems at year-end.
Here's what each method actually does, in plain English.
Straight-Line Depreciation
This is the one most people picture when they hear "depreciation." You take an asset's cost, subtract what you expect to recover when you eventually dispose of it (the salvage value), and spread the difference evenly across its useful life.
A laptop bought for $1,200 with a $200 expected salvage value and a 3-year useful life depreciates by $333.33 a year. The same amount every single year, no surprises.
Why it's the default: it's predictable, it's easy to explain to a non-accountant, and it's what most accounting standards expect for general business assets. If you only ever implement one depreciation method properly, this is the one.
Declining Balance Depreciation
Instead of an even amount each year, declining balance applies a fixed percentage to whatever the asset's current book value is. So the depreciation charge is largest in year one and shrinks every year after.
This models reality better for assets that genuinely lose most of their value early. Vehicles and certain machinery being the classic examples. A car depreciates far more in year one than in year seven, and declining balance reflects that instead of pretending the loss is linear.
The catch: it's more work to track (the charge changes every period, forever, unless you switch to straight-line partway through to force it to zero), and most small organisations (schools, clinics, retail, professional services) don't actually own the kind of rapidly-depreciating heavy equipment where the extra complexity pays for itself.
Units of Production Depreciation
Rather than time, this method ties depreciation to usage. Machine hours run, units manufactured, kilometers driven. An asset that sits idle for a month depreciates by nothing that month; one worked hard depreciates faster.
It's the most accurate method for manufacturing equipment with genuinely variable usage, and the least practical for almost everything else, since it requires someone to actually log usage figures on an ongoing basis. A real operational commitment, not just a bookkeeping choice.
Capital Allowance (Tax Depreciation)
Here's where it gets genuinely confusing for a lot of business owners: the depreciation you record for your accounting books is often not the depreciation your tax authority actually lets you claim.
Most tax jurisdictions run their own separate schedule (commonly called capital allowance) with its own rules: an Initial Allowance claimed in the year of purchase, then an Annual Allowance claimed every year after at a fixed rate, calculated completely independently of whatever method you're using for your accounting books. When you eventually sell or scrap the asset, there's a further "true-up" calculation. A balancing allowance if you claimed less than the asset's tax value implied, or a balancing charge if you claimed more.
This means a properly run fixed-asset register isn't tracking one depreciation figure per asset. It's tracking two, on two separate schedules, that rarely land on the same number in any given year.
So Which Method Should You Actually Use?
For most organisations, the honest answer is: straight-line for your accounting books, capital allowance for your tax filing: run as two parallel schedules, not one number doing double duty.
That's a deliberate choice, not a compromise. Declining balance and units of production solve real problems for asset-heavy manufacturers and fleets, but they add real ongoing complexity that most schools, clinics, retailers, and professional-services firms don't need to take on. Straight-line plus a properly maintained tax book covers the overwhelming majority of what a growing organisation actually has to report. Accurately, and without an accountant re-deriving your numbers from scratch every March.
What This Looks Like in Dozz.ai
Dozz.ai runs exactly this dual-book model natively: a straight-line accounting schedule and a capital allowance tax schedule, generated automatically the moment an asset is assigned a depreciation category. Not re-typed into a spreadsheet every reporting period. Change a category's useful life or salvage rule later, and you choose whether it applies going forward only or gets recalculated across every asset already on it. Dispose of or write off an asset, and both books close out correctly. Including the balancing allowance/charge calculation on the tax side that a lot of manual trackers quietly skip.
You don't need to be an accountant to keep a clean fixed-asset register. You need the two numbers that actually matter calculated correctly, every period, without anyone having to remember to update them.
See how Dozz.ai's depreciation module works. Start your free 30-day trial, no credit card needed.