What is the difference between depreciation and capital allowances?

Depreciation is an accounting method that spreads the cost of a fixed asset over its useful life, while capital allowances are the HMRC-approved tax relief that lets you deduct a proportion of that cost from your taxable profits. The two concepts serve different purposes: one for financial reporting and the other for calculating tax.

Because the rules and timing differ, the figure shown as an expense in your accounts is rarely the same as the amount you can claim against corporation tax. This guide explains the practical differences, how each is calculated, and the steps UK early-stage founders and e-commerce sellers should follow to stay compliant and maximise legitimate relief.

Why the distinction between accounting and tax treatment exists

Financial accounts prepared under UK GAAP or FRS 102 aim to show a true and fair view of business performance to directors, lenders and investors. Depreciation is therefore based on the economic life of the asset and how management expects to use it. Tax law, however, is set by Parliament and uses capital allowances to encourage investment while preventing immediate full deduction of large purchases. This separation means the profit in your accounts will usually differ from the profit you declare to HMRC.

The difference creates timing variations that are reconciled each year on your corporation tax return. Understanding both treatments lets you forecast cash flow more accurately and avoid unexpected tax bills.

How depreciation works in your accounts

Depreciation is charged in the profit and loss account to reflect the wearing out of assets such as computers, machinery, shop fittings or vehicles. Common methods include straight-line, reducing balance and units of production. You choose the method and estimated useful life that best matches the asset’s expected benefit to the business.

• Record the asset at cost on the balance sheet.
• Subtract any residual value you expect to recover at the end of its life.
• Divide the depreciable amount by the number of years (or months) of useful life.
• Post a monthly or yearly journal that reduces both profit and the asset’s net book value.

Depreciation is an estimate. It does not involve cash leaving the business in the year it is charged, yet it reduces reported profit. This is important when you discuss performance with investors or apply for finance.

How capital allowances work for tax

Capital allowances replace depreciation in the tax computation. Instead of using accounting estimates, you follow HMRC’s prescribed rates and pools. The main pool covers most plant and machinery at the prevailing rate. Special rate pools exist for assets with longer lives such as integral features in buildings or cars with higher CO₂ emissions. Annual Investment Allowance (AIA) may allow immediate deduction of qualifying expenditure up to a set limit in the year of purchase.

Unlike depreciation, capital allowances are not charged in your accounting records. You calculate them separately on the corporation tax computation and add back the accounting depreciation before deducting the tax allowance. The result is usually a different taxable profit.

Practical example – buying a delivery van

Assume an e-commerce seller buys a van for stock deliveries. In the accounts the business might depreciate the van over five years using the straight-line method, charging one fifth of the cost each year. This reduces accounting profit evenly.

For tax the same van may qualify for the main pool or, depending on CO₂ emissions, the special rate pool. If the Annual Investment Allowance is available the full cost might be deductible in year one, creating a timing difference: lower taxable profit and lower corporation tax in the first year, with higher tax in later years when capital allowances reduce but accounting depreciation continues. The difference is tracked as a deferred tax balance in the accounts if material.

Keep purchase invoices, delivery notes and a fixed asset register that records both the accounting cost and the tax written-down value for each asset. This makes it easier to prepare accurate computations when filing the company tax return.

Common pitfalls and how to avoid them

Many early-stage founders record depreciation and assume the same figure can be used on the tax return. HMRC will disallow this and require the accounting depreciation to be added back. Failing to make the adjustment can trigger enquiries or penalties.

Another error is claiming capital allowances on assets that do not qualify, such as certain land improvements or entertainment equipment. Check the HMRC list of qualifying expenditure each time rules change.

Disposals also create differences. When you sell an asset the accounting gain or loss is based on net book value, while the tax balancing charge or allowance is based on the tax written-down value in the relevant pool. Record both figures and adjust the corporation tax computation accordingly.

Review your fixed asset register at least once a year. Reconcile the total depreciation charged in the accounts to the capital allowances claimed on the tax return. Any unreconciled difference may indicate an error that should be corrected before submission.

Steps to manage both treatments in your startup

1. Decide on a clear accounting policy for depreciation and document the useful lives and methods you apply to each class of asset.
2. Maintain a fixed asset register that shows cost, accumulated depreciation, net book value, capital allowances claimed to date and tax written-down value.
3. When preparing management accounts, charge depreciation as normal.
4. At year end, add back the total depreciation in the corporation tax computation and insert the capital allowances figure instead.
5. If you are preparing accounts that will be filed at Companies House, ensure the depreciation policy is applied consistently and disclosed where required.
6. Use accounting software that can track both book and tax values, or keep a simple spreadsheet that reconciles the two each period.
7. Check current HMRC guidance on GOV.UK before claiming Annual Investment Allowance or writing off assets, because the limits and rates can change.

These steps reduce the risk of errors, speed up tax return preparation and give you a clearer picture of both reported profit and cash tax payable.

How this affects cash flow and pricing decisions

Because capital allowances often front-load tax relief, a new business can preserve cash in the early years when every pound matters. This improved cash position can be factored into pricing, allowing more competitive margins without sacrificing reinvestment in stock or marketing.

When forecasting, prepare two versions of your profit and loss: one showing accounting depreciation for management and investors, and another showing the tax-adjusted profit after capital allowances. The difference helps you anticipate corporation tax payments nine months after the year end and avoid cash-flow surprises.

For e-commerce sellers investing in warehouse racking, packaging machines or website servers, understanding the timing of tax relief lets you plan capital expenditure around financial year ends for maximum benefit within the current rules.

Frequently asked questions

Related reading: How is VAT applied to subscription boxes and membership sites?, Practical ways to improve cash flow for cash-strapped startups, What counts as trading income on my self assessment tax return?. Browse all tax & finance guides or apply to Loomworks.