Division 40 vs Division 43: The Core Distinction for Dental Practices
When a dental practice invests in equipment or fit-out, the first question for the bookkeeper and accountant is whether the expenditure is Division 40 (plant and equipment) or Division 43 (capital works). This distinction determines the depreciation rate, the available method, and whether the instant asset write-off applies.
Division 40 covers all removable clinical and operational equipment: dental chairs, X-ray systems, autoclaves, handpieces, sterilisation equipment, intraoral cameras, dental lasers, computers, and software. Each item has a specific effective life published in ATO Tax Ruling TR 2023/1, which is updated periodically. Division 40 assets can use either the diminishing value (DV) method or the prime cost (PC) method, and qualifying small business entities can apply the instant asset write-off for assets below the threshold.
Division 43 covers the structural fit-out of the dental premises: the plumbing for chair connections, compressed air lines, cabinetry built into the walls, flooring, ceiling, ventilation, and other capital improvements to the building. Division 43 is always 2.5% per year over 40 years. There is no accelerated depreciation for capital works, and the instant asset write-off does not apply.
ATO Effective Lives for Dental Equipment
| Equipment Item | Div. | Effective Life | DV Rate | PC Rate | Notes |
|---|---|---|---|---|---|
| Dental chair (patient) | 40 | 10 yrs | 20% | 10% | Includes unit, light and bracket tray |
| OPG panoramic X-ray | 40 | 10 yrs | 20% | 10% | Digital sensor included with unit |
| CBCT scanner | 40 | 10 yrs | 20% | 10% | Typically above IAWO threshold |
| Intraoral X-ray unit | 40 | 5 yrs | 40% | 20% | Handheld or wall-mounted units |
| Dental handpieces | 40 | 3 yrs | 66.67% | 33.33% | High-speed and slow-speed; often IAWO eligible |
| Autoclave / steriliser | 40 | 10 yrs | 20% | 10% | Class B autoclaves |
| Dental compressor | 40 | 10 yrs | 20% | 10% | Oil-free dental-grade compressor |
| Intraoral camera | 40 | 5 yrs | 40% | 20% | Digital or USB models |
| Curing light | 40 | 3 yrs | 66.67% | 33.33% | LED curing lights |
| Dental laser | 40 | 10 yrs | 20% | 10% | Diode, Er:YAG, CO2 types |
| Computers and tablets | 40 | 4 yrs | 50% | 25% | Often below IAWO threshold |
| Structural fit-out | 43 | 40 yrs | 2.5% | 2.5% | No IAWO; straight-line only |
Source: ATO Tax Ruling TR 2023/1. DV = Diminishing Value. PC = Prime Cost. Rates should be confirmed with your accountant as rulings can be updated.
Instant Asset Write-Off for Dental Equipment
The instant asset write-off (IAWO) allows small business entities to immediately deduct the full cost of eligible assets in the year of purchase rather than depreciating over the effective life. To qualify, the practice must have an aggregated annual turnover below $10 million, and the asset must cost less than the current IAWO threshold. Check the ATO's current IAWO threshold as it changes from time to time.
| Asset Example | Cost (approx.) | IAWO Eligible? | Treatment |
|---|---|---|---|
| Entry dental chair | $18,500 | Yes (if below threshold) | Full deduction in purchase year |
| Premium chair with integrated unit | $28,000 | No (above threshold) | Depreciate 20% DV over 10 years |
| CBCT scanner | $140,000 | No (above threshold) | Depreciate 20% DV over 10 years |
| 6 handpieces | $4,200 | Yes | Full deduction in purchase year |
| Structural fit-out | $90,000 | No (Div 43) | 2.5% per year over 40 years |
Setting Up the Dental Fixed Asset Register in Xero
Every depreciable asset in a dental practice should be set up individually in Xero's Fixed Assets module. The asset register must record: asset name and description, purchase date, purchase price (exclusive of GST), asset type, depreciation method (diminishing value or prime cost), effective life in years, and calculated annual depreciation. Xero calculates depreciation automatically once the asset is correctly set up and posts it to the depreciation expense account each period.
The most common errors in dental practice fixed asset registers are: assets posted directly to expense accounts and never registered; grouped purchases (such as a chair and its accessories) registered as a single asset with an incorrect total value; fit-out costs included in plant and equipment at Division 40 rates when they should be at Division 43 rates; and assets that have been sold or scrapped still sitting on the register and generating depreciation expense.
A useful starting resource for checking current effective lives is the ATO's Depreciation and Capital Allowances Tool. Your accountant prepares the formal depreciation schedule, but the underlying data comes from the bookkeeper's fixed asset register in Xero.
Watch: Dental Equipment Depreciation Explained
Read the full video transcript
If you run a dental practice in Victoria, the equipment you invest in represents a significant part of your business assets, and how you claim depreciation on those assets can make a material difference to your tax position each year. Today I want to walk through how the ATO treats dental equipment depreciation, what the effective lives are for the most common items, and where the instant asset write-off fits in.
There are two main categories of assets in a dental practice. Division 40 covers plant and equipment, which includes all the clinical and operational items like dental chairs, X-ray machines, autoclaves, handpieces, intraoral cameras, and computers. These use the ATO's effective life schedule from Tax Ruling 2023 slash 1. Division 43 covers capital works, which is the fit-out of the premises itself. Capital works depreciate at two point five percent per year over forty years, and the instant asset write-off does not apply to Division 43.
The ATO's effective life ruling gives dental chairs a ten year life, which translates to a twenty percent diminishing value rate. OPG panoramic X-ray machines also have a ten year life at twenty percent. CBCT scanners have a ten year life at twenty percent. Intraoral X-ray units have a five year life at forty percent. Dental handpieces have only a three year effective life, which gives a sixty-seven percent diminishing value rate. Autoclaves and dental lasers have a ten year life. Intraoral cameras and curing lights are five and three years respectively. Computers are four years.
The instant asset write-off is available to small business entities with an aggregated annual turnover below ten million dollars. Any individual asset costing less than the current threshold can be written off in full in the year of purchase. So a set of handpieces costing four thousand dollars is immediately deductible. A dental chair at eighteen thousand five hundred sits just under the twenty thousand dollar threshold and qualifies for immediate write-off. A CBCT scanner at one hundred and forty thousand sits well above the threshold and must be depreciated over its effective life.
In Xero, every depreciating asset needs to be set up in the fixed asset register with the correct effective life, method, and purchase price. Xero calculates depreciation automatically from there. If assets are being posted directly to expense accounts instead of the asset register, your depreciation claims are likely wrong. True Tally helps dental practices across Victoria set up and maintain accurate fixed asset registers in Xero. Book a free call at truetally.com.au or call 0468 159 950.
Last updated July 2026
Frequently Asked Questions
What is the ATO effective life of a dental chair?
Under ATO Tax Ruling TR 2023/1, a dental chair has an effective life of 10 years, giving a diminishing value rate of 20% per year.
Can I claim the instant asset write-off on a new dental chair?
If your practice qualifies as a small business entity and the chair costs less than the current IAWO threshold, yes. Check the ATO's current threshold as it changes. A chair above the threshold must be depreciated at 20% diminishing value over 10 years.
Is a dental fit-out depreciated differently from equipment?
Yes. The structural fit-out is Division 43 capital works at 2.5% per year over 40 years. Individual removable items within the fit-out are Division 40 at their applicable effective life rates.
Dental practice with assets not yet in Xero?
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