How to Calculate a Balancing Allowance on Asset Disposal

To calculate a balancing allowance on asset disposal, subtract the disposal value of the asset from the remaining balance in its capital allowances pool; if the pool balance is higher, the difference is your balancing allowance and it reduces your taxable profit for the period. The calculation is simple arithmetic. The harder part is knowing whether a balancing allowance is actually available on the disposal in front of you, because that depends on which pool the asset sits in.

The Calculation, Step by Step

You need two numbers: the tax written down value of the pool just before the disposal, and the disposal value of the asset leaving it.

Take the pool balance. Subtract the disposal value. If the result is positive, that is your balancing allowance, and you deduct it from your profits for the period. If the result is negative, you have a balancing charge instead, which is added to your profits.

A worked example. You elected short-life asset treatment for a piece of workshop equipment when you bought it. After several years of writing down allowances, the single asset pool holding it has a balance of £8,000. You sell the equipment for £3,000. Pool balance minus disposal value is £8,000 − £3,000 = £5,000. That £5,000 is your balancing allowance.¹

If the asset was destroyed and you received no insurance money, the disposal value is zero and the entire remaining pool balance becomes your balancing allowance.²

Finding Your Pool Balance

The pool balance (often called the tax written down value) starts with the original cost of the asset. Add any capital improvements. Subtract every writing down allowance, Annual Investment Allowance claim, or first-year allowance you have taken in prior periods. Your previous tax returns and internal asset register should show that running total.¹

If you claimed the full cost of the asset under the Annual Investment Allowance or full expensing in the year of purchase, the pool balance is zero. In that case there is no balancing allowance possible on disposal: any proceeds you receive will trigger a balancing charge instead.

Finding Your Disposal Value

The disposal value depends on how the asset left the business. Section 61 of the Capital Allowances Act 2001 sets the figure for each type of event:

If you sell the asset, the disposal value is the net sale proceeds, plus any insurance money relating to the condition of the asset at the time of sale.
If the asset is destroyed or dismantled, the disposal value is any insurance payout or compensation received.
If you permanently lose possession, any insurance or compensation received is the disposal value.
If the asset starts being used for non-business purposes, that switch triggers a disposal event at market value.
If your qualifying activity permanently stops, every asset in your pools triggers a disposal event.³

Deducting Selling Costs

The Act refers to the “net proceeds” of a sale, which means direct selling expenses come off the gross figure. Sell a commercial vehicle for £10,000, pay £600 in auction fees and £200 in transport to the buyer, and the disposal value entering your pool is £9,200. That matters: a lower disposal value leaves a larger pool balance, which either increases your balancing allowance or shrinks any balancing charge. Keep the invoices for every cost you deduct, because HMRC can ask you to substantiate the net figure.

When a Balancing Allowance Is Actually Available

This is the point most businesses get wrong. The calculation above produces a number on paper, but whether you can claim it depends on the type of pool.

Main Pool and Special Rate Pool

For assets in the main pool or special rate pool, you can only claim a balancing allowance when your business permanently stops trading.⁴ During normal trading, selling an asset from one of these shared pools just reduces the pool balance by the disposal value. The pool carries on. If the balance tips below zero, you get a balancing charge for that negative amount, but no standalone balancing allowance arises from the disposal of an individual asset.

Single Asset Pools

Single asset pools are different. You can claim a balancing allowance any time you dispose of the asset in one of these pools, whether or not the business continues.¹ Two categories of asset sit in their own pool:

Private use assets. Equipment and cars used partly for personal purposes cannot go into the main or special rate pool. Each gets its own single asset pool.⁵ When you dispose of one, you run the usual calculation, but only the business-use proportion is deductible. If a car was 70% business use and the pool balance minus disposal value is £2,000, you claim £1,400.

Short-life assets. A short-life asset election keeps an item out of the main pool so that if it loses value faster than the standard writing down rate, you can claim the shortfall as a balancing allowance on disposal. The election must be made within the normal time limit for amending the tax return for the period the expenditure was incurred, and once made it cannot be reversed. For expenditure incurred from April 2011 onward, the asset stays in its single asset pool for 8 years after the end of the chargeable period in which the expenditure was incurred. If you have not disposed of it by then, the remaining balance transfers into the main pool and the chance of a balancing allowance on that specific item is lost unless the business ceases.⁶

On Cessation

When the business permanently stops, every pool goes through a final disposal reckoning. For assets you sell, the disposal value is the net sale proceeds. For assets you keep, give away, or transfer to personal use, the disposal value is the market value at the date trading ceases.⁴ Subtract the total disposal values from each pool balance. Positive leftover is a balancing allowance; a shortfall is a balancing charge.

This final period can throw up large balancing allowances where specialist equipment has lost resale demand, and equally throw up unexpected balancing charges on items that held value better than the writing down rate assumed. Professional valuations for high-value or unusual assets are worth paying for, because HMRC can challenge disposal values that look unreasonably low.

When the Calculation Produces a Balancing Charge Instead

If the disposal value exceeds the remaining pool balance, you have a balancing charge rather than an allowance, and it is added to your taxable profit for the period.¹ Balancing charges can arise in any pool and any year, not only on cessation. The charge is capped at the original qualifying expenditure, so you will never repay more tax than you originally saved.

This catches out businesses that claimed full relief upfront. If you took the Annual Investment Allowance or full expensing on the whole cost, the pool balance is zero, so every pound of disposal proceeds becomes a balancing charge. Companies that used the permanent 100% full expensing allowance for main rate expenditure from April 2023 should expect a balancing charge whenever a fully expensed asset is later sold.⁷ The same logic applies at half strength to the 50% first-year allowance for special rate expenditure.

Sales to Connected Persons

Selling an asset to a connected person at below market value will not enlarge your balancing allowance. HMRC applies a market value rule where the buyer controls the seller, the seller controls the buyer, both are controlled by the same person, or the parties are otherwise connected. Capital allowances for both sides are then calculated as if the sale took place at market value.⁸ A separate tax advantage test can trigger the same market value treatment where the main benefit of the transaction looks like a tax advantage.

Reporting the Allowance

Balancing allowances are claimed through your capital allowances computation and included with your tax return according to how the business is set up:

Sole traders claim through the capital allowances section of the Self Assessment return.
Partnerships claim through the partnership tax return.
Limited companies submit a capital allowances calculation with the Company Tax Return (CT600).⁹

HMRC’s helpsheet HS252 walks through the capital allowances boxes on the Self Assessment return and is worth reading if you are filing manually.¹⁰ Commercial tax software will usually prompt for the disposal value and run the adjustment itself, but the figures you feed in are only as good as the pool history and the net proceeds you have documented.

1
GOV.UK. HS252 Capital Allowances and Balancing Charges 2025
2
Legislation.gov.uk. Capital Allowances Act 2001, Part 3, Chapter 7 – Balancing Adjustments
3
Legislation.gov.uk. Capital Allowances Act 2001, Section 61
4
GOV.UK. Capital Allowances When You Sell an Asset
5
GOV.UK. HS252 Capital Allowances and Balancing Charges 2024
6
Legislation.gov.uk. Capital Allowances Act 2001, Part 2, Chapter 9 – Short-Life Assets
7
GOV.UK. Capital Allowances – Permanent Full Expensing for Companies Investing in Plant and Machinery
8
GOV.UK. CA13100 – General – Connected Person and Control Sales
9
GOV.UK. Claim Capital Allowances – How to Claim
10
GOV.UK. Capital Allowances and Balancing Charges (Self Assessment Helpsheet HS252)