Full Expensing Isn't a Shopping List: A December Equipment Test for UK SMEs

December is peak season for a particular kind of sales call. An equipment supplier rings, mentions your year-end, and explains that full expensing makes the purchase almost painless. The tax logic is real. The commercial logic often is not.

Capital allowances are a timing benefit, not a discount. A company paying corporation tax at 25% that spends £100,000 on qualifying kit may save £25,000 in tax, but it has still parted with £100,000 of cash. For an SME with a December accounting period end, the question is not 'how much relief can I generate?' but 'which of these purchases would I make anyway?'

Here is a practical filter for the final weeks of 2026.

Start with the sieve, not the shopping list

Full expensing is generous, but it is not a universal allowance. Run each candidate asset through these tests before anyone signs a purchase order.

• Structure matters. Full expensing is available to companies within the charge to corporation tax. Sole traders and partnerships rely on the Annual Investment Allowance and writing-down allowances instead.
• Asset type matters. Main-rate plant and machinery qualifies for 100% full expensing. Integral features and long-life assets in the special rate pool attract a 50% first-year allowance, with the remainder written down at 6%.
• Some assets are excluded. Cars do not qualify. Neither do assets acquired from a connected party, assets acquired through a sale-and-leaseback, or anything the business already owned.
• Second-hand kit is limited. Used equipment does not qualify for full expensing, although it can usually be covered by the Annual Investment Allowance.
• The AIA still does heavy lifting. The £1m limit is permanent and available to companies and unincorporated businesses alike. It can be spread across pools, so it remains useful for special-rate items and for unincorporated firms.

A useful discipline is to write the asset category on the quote. If nobody in the business can say whether the item is main-rate, special-rate or excluded, the tax tail is already wagging the commercial dog.

The date that decides the claim

Relief follows the accounting period in which expenditure is incurred. That is not the date on the purchase order, and it is not the date the supplier takes your deposit.

Broadly, expenditure is incurred when the business has an unconditional obligation to pay. Delivery, installation and the transfer of risk all matter. A deposit paid in December for kit that arrives in February is normally a February asset, not a December one. An invoice dated 30 December for equipment still sitting in the supplier's warehouse is a question waiting to be asked.

December year-ends compress this problem. Installers are thin on the ground between Christmas and New Year, hauliers are expensive, and suppliers know they have leverage. If the equipment will not be delivered and operational until January, treat it as a January purchase and budget accordingly. Do not backdate paperwork to manufacture a claim.

Cash, hire purchase and the leasing trap

The way an asset is financed changes the allowance, not just the cash-flow profile.

• Hire purchase is generally treated as a purchase. The business can usually claim capital allowances on the full capital cost, even though it pays in instalments.
• Finance leases and operating leases do not normally attract capital allowances. The rentals are deducted as a business expense instead.
• Asset finance and chattel mortgages can preserve working capital, but the agreement wording decides the tax treatment. Read the termination and ownership clauses before assuming you own anything.

For an owner-manager weighing cash against finance, the comparison is straightforward. Paying cash saves interest but drains the bank account before the quiet first quarter. Financing keeps cash in the business but adds a fixed cost. Neither route makes a bad purchase good.

VAT: claim on the net figure

A VAT-registered business that can recover input VAT should claim capital allowances on the net cost. Recoverable VAT is not part of the expenditure.

Where VAT is irrecoverable — because of partial exemption, a non-business use, or a blocked category — it can usually be capitalised and included in the allowance claim. Mixing the two is a common error. So is forgetting that installation and delivery charges often follow the same VAT treatment as the equipment itself.

What to have in the file

If HMRC asks, the paperwork should tell a coherent story without anyone having to reconstruct it from memory.

1. Supplier invoice dated within the accounting period.
2. Signed delivery note or installation certificate.
3. Serial numbers or asset tags.
4. An entry in the fixed asset register, with the pool allocation.
5. A board minute or partner resolution approving the purchase.
6. The finance agreement, if any, with the ownership terms highlighted.
7. Evidence of business use, particularly for dual-purpose items.
8. The VAT recovery calculation.
9. A short note explaining why the asset was needed.

That last item is not a tax requirement, but it is the one that exposes a tax-driven purchase fastest.

Five purchases to walk away from

• Kit that cannot be used until spring. Relief this year does not compensate for a machine sitting idle under a sheet.
• Second-hand equipment from a connected company. Full expensing will not apply, and the connected-party rules invite scrutiny.
• A car dressed up as a commercial vehicle. Double cab pickups have been treated as cars for capital allowances and benefit-in-kind since 2024 in most cases. Check the definition before believing the salesman.
• Assets bought mainly for private use. The business-use proportion limits the claim, and the benefit-in-kind paperwork follows close behind.
• A lease described as a purchase. If the business never owns the asset, the allowance usually belongs somewhere else.

The ten-day sprint

With 31 December 2026 in sight, a sensible sequence looks like this. Confirm the accounting period end and the pool allocation for each candidate asset. Obtain written confirmation of delivery dates, not verbal assurances. Decide whether cash or finance preserves the first-quarter runway. Recover or capitalise VAT correctly. Update the fixed asset register before the invoice is filed, not after the year-end accounts are drafted.

Then ask the commercial question one more time: would this purchase survive a year in which the tax relief did not exist? If the answer is no, the allowance is not a reason to buy. It is a reason to wait.