Can You Claim AIA on Second-Hand Assets for Your Dental Practice?
The short answer is yes, in most cases. The Annual Investment Allowance (AIA) is available on most plant and machinery, including second-hand assets, provided they are unused and not previously owned by the claimant [1]. For a dental practice, this means you can claim 100% tax relief on the cost of second-hand dental chairs, X-ray machines, autoclaves, compressors, and other equipment, as long as you are the first business owner of that specific item.
This is a valuable relief for dentists buying equipment for a new practice, expanding an existing one, or replacing older items. The AIA limit is £1 million per year until 31 March 2026 [2][1]. However, there are important conditions and exclusions that every practice owner should understand before making a claim.
What Is the Annual Investment Allowance (AIA)?
The AIA is a capital allowance that gives you 100% tax relief on qualifying plant and machinery costs in the year you buy them. Instead of spreading the cost over several years through writing-down allowances, you deduct the full cost from your taxable profits immediately. For a dental practice paying corporation tax at 19% or 25%, this can mean a significant tax saving in the year of purchase.
You can claim AIA on most plant and machinery up to the AIA amount [2]. The current limit is £1 million per year, which covers the vast majority of dental equipment purchases. This limit applies per business, not per practice site, so a group practice with multiple surgeries can claim up to £1 million in total across all its locations.
Can You Claim AIA on Second-Hand Assets? The Key Rules
Yes, second-hand assets qualify for AIA if they are new to the business and have not been used by a connected party before [1]. HMRC guidance states that the asset must be unused and not have been previously owned by the claimant or a person connected with the claimant [1].
This means you can buy a used dental chair from a supplier who has never used it in a business, or from a practice that is closing down, and claim AIA on the purchase price. However, you cannot claim AIA on items you owned for another reason before you started using them in your business [2]. For example, if you already owned a dental chair personally and then started using it in your practice, you cannot claim AIA on it.
Similarly, you cannot claim AIA on items given to you or your business [2]. If a retiring dentist gives you their old equipment for free, you cannot claim AIA on the market value. In that case, you would use the market value as the cost for capital allowances purposes, but you would claim writing-down allowances instead of AIA [3].
What Qualifies as Plant and Machinery for a Dental Practice?
Most equipment you use in your dental practice qualifies as plant and machinery. This includes:
- Dental chairs and delivery units
- X-ray machines, including OPG and CBCT scanners
- Autoclaves and sterilisation equipment
- Compressors and suction units
- Computers, practice management software, and servers
- Dental laboratory equipment
- Furniture and fittings used in the practice
You can claim capital allowances on equipment, machinery, and business vehicles, for example vans, lorries or business cars [3]. However, cars have specific rules and do not qualify for AIA [1].
What Does Not Qualify for AIA?
AIA cannot be claimed on cars, assets used for leasing, or assets that are not plant and machinery [1]. For a dental practice, the main exclusions are:
- Cars, Business cars do not qualify for AIA. You claim writing-down allowances instead, at 18% or 6% per year depending on CO2 emissions.
- Assets used for leasing, If you buy equipment to lease to another practice, you cannot claim AIA on it.
- Buildings and land, The cost of the practice building itself does not qualify for AIA. However, you may be able to claim Structures and Buildings Allowance at 3% per year on qualifying construction costs.
- Assets acquired from a connected person, AIA is not available on assets acquired from a connected person, even if the asset is second-hand [1]. This includes purchases from a spouse, business partner, or a company you control.
How to Value Second-Hand Assets for AIA
In most cases, the value is what you paid for the item [3]. For a second-hand dental chair bought from a supplier for £5,000, you claim AIA on £5,000. Simple enough.
However, there are two situations where you use market value instead of the actual price paid:
- If you owned the item before you started using it in your business, For example, you bought a dental chair for personal use and later brought it into the practice. You use the market value at the date you started using it in the business [3].
- If the item was a gift, If someone gave you the equipment, you use the market value at the date you received it [3].
In both cases, you cannot claim AIA on these items. You claim writing-down allowances instead [2][3].
Buying a Dental Practice with Existing Equipment
This is a common scenario for practice buyers. When you buy a dental practice as a going concern, you acquire the equipment along with the goodwill, premises, and other assets. The question is: can you claim AIA on the second-hand equipment you acquire as part of the purchase?
The answer depends on whether the seller has previously claimed capital allowances on that equipment. If the seller has claimed AIA or other allowances, the equipment is not "unused" for capital allowance purposes. You cannot claim AIA on it. Instead, you claim writing-down allowances based on the value you allocate to the equipment in the purchase agreement.
This is where a practice valuation and proper asset allocation become critical. You need to agree with the seller on a fair split of the purchase price between goodwill, equipment, premises, and other assets. The equipment value you agree will form the basis of your capital allowance claim going forward.
If the seller has not claimed any capital allowances on the equipment (unlikely but possible), you may be able to claim AIA. However, this is rare, and you should take professional advice before assuming it applies.
Practical Example: Buying Second-Hand Equipment for Your Practice
Dr. Patel is a practice owner buying a second-hand dental chair and X-ray machine from a retiring dentist. She pays £8,000 for the chair and £12,000 for the X-ray machine. Both items are unused by Dr. Patel and not connected to her. She can claim AIA on the full £20,000 cost in the year of purchase, reducing her taxable profit by £20,000.
If Dr. Patel is a limited company paying corporation tax at 19%, the tax saving is £3,800. If she is a sole trader paying higher-rate income tax at 40%, the saving is £8,000. The AIA makes a significant difference to cash flow in the year of investment.
Now consider a different scenario. Dr. Patel buys a practice from a seller who has claimed AIA on all the equipment. She pays £500,000 for the practice, with £100,000 allocated to equipment in the sale agreement. She cannot claim AIA on that £100,000 because the equipment is not "unused" for capital allowance purposes. Instead, she claims writing-down allowances at 18% per year on the reducing balance, giving her £18,000 relief in year one, then £14,760 in year two, and so on.
What If You Use the Asset Partly for Business and Partly for Private Use?
If you are a sole trader or partnership and you use an asset partly for business and partly for private purposes, you cannot claim the full value of the item [2]. You must restrict the AIA claim to the business-use proportion.
For example, if you buy a laptop for £2,000 and use it 60% for practice work and 40% for personal use, you claim AIA on £1,200 (60% of £2,000). The remaining £800 does not qualify for any capital allowance because it relates to private use.
Selling an Asset After Claiming AIA
If you sell the item after claiming AIA, you may need to pay tax [2]. This is because the AIA gave you 100% relief on the cost, so any sale proceeds are effectively a balancing charge. The charge is added to your taxable profits in the year of sale.
For example, if you bought a dental chair for £10,000, claimed AIA, and sold it three years later for £4,000, you would add £4,000 to your taxable profits in the year of sale. This is the same as saying you have no remaining tax-written-down value, so the full sale proceeds are taxable.
Choosing Between AIA and Other Capital Allowances
If an item qualifies for more than one capital allowance, you can choose which one to use [3]. For most dental equipment, AIA is the best option because it gives 100% relief immediately. However, there may be situations where you prefer to use writing-down allowances instead, for example if you want to spread the relief over several years to manage your tax position.
You can also choose to claim AIA on some items and writing-down allowances on others in the same year. The choice is yours, but you should consider the overall tax position of your practice before deciding.
How to Claim AIA on Your Tax Return
Claiming AIA is straightforward. You include the qualifying expenditure in the capital allowances section of your tax return. For a limited company, this is in the corporation tax return (CT600). For a sole trader or partnership, it is in the self-assessment return.
You need to keep records of the purchase, including invoices, receipts, and any agreements that show the cost and date of acquisition. If you are buying a practice with equipment, keep the sale agreement and the asset allocation schedule.
For more detailed guidance on how capital allowances interact with your overall tax position, see our practice accounting services page.
Common Mistakes to Avoid
Here are the most common errors dentists make when claiming AIA on second-hand assets:
- Claiming AIA on assets from a connected person, AIA is not available on assets acquired from a connected person, even if the asset is second-hand [1]. This includes purchases from your spouse, business partner, or a company you control.
- Claiming AIA on assets you already owned, You cannot claim AIA on items you owned for another reason before you started using them in your business [2].
- Claiming AIA on gifted assets, You cannot claim AIA on items given to you or your business [2]. Use market value and claim writing-down allowances instead.
- Forgetting to restrict for private use, If you are a sole trader or partnership and you use the asset partly for private purposes, you must restrict the AIA claim to the business-use proportion [2].
- Claiming AIA on cars, Cars do not qualify for AIA [1]. Claim writing-down allowances based on CO2 emissions.
Planning Your Equipment Purchases
The AIA limit of £1 million is generous, but it is not permanent. The current limit is confirmed until 31 March 2026 [1]. After that, the limit may revert to £200,000, which was the previous permanent level. If you are planning significant equipment purchases, consider timing them before the limit changes.
For practice owners buying a new practice or expanding, the AIA can make a substantial difference to your tax bill. A practice purchase financial due diligence guide can help you understand how to structure the acquisition to maximise capital allowance claims.
If you are an associate considering buying equipment for your own use, remember that you can claim AIA on equipment you buy for your work, provided you are self-employed and the equipment is used wholly or mainly for your practice work. See our associate tax services for more details.
Final Thoughts
Claiming AIA on second-hand assets is a legitimate and valuable tax relief for dental practices. The key is to understand the conditions: the asset must be new to your business, not previously owned by you or a connected person, and must qualify as plant and machinery. With the £1 million limit, most practices can claim full relief on their equipment purchases in the year of acquisition.
However, the rules around connected persons, gifts, and assets you already owned can be tricky. If you are buying a practice with existing equipment, the position is more complex and depends on the seller's capital allowance history. Professional advice is essential to get the allocation right and avoid missing out on relief.
For a full review of your practice's capital allowance position, including AIA claims on second-hand assets, contact our team of dental accountants who specialise in the dental sector.