Capital allowances calculator — AIA, WDA & pools
Claim the capital allowances you're entitled to. We handle the Annual Investment Allowance, writing-down allowances and the main/special-rate pools, pro-rated for short accounting periods.
- Annual Investment Allowance up to the £1m cap
- Writing-down allowances on a reducing balance
- Main and special-rate pools carried forward
- Feeds your annual accounts and CT600
What capital allowances are
When you buy equipment, machinery, tools or vehicles for the business you can't deduct the cost as an ordinary expense — you claim capital allowances instead. The Annual Investment Allowance lets most businesses deduct the full cost of qualifying plant and machinery in the year of purchase, up to £1 million a year, so the relief is usually immediate.
Pools, writing-down allowances and full expensing
Spending above the AIA, or assets that don't qualify for it, goes into a pool and attracts writing-down allowances each year on a reducing balance — 18% for the main pool and 6% for the special-rate pool (integral features, long-life assets). Limited companies can also claim full expensing: a 100% first-year deduction on most new main-rate equipment, with 50% on special-rate.
How we handle it
Add each asset with its cost, date and pool, and we apply the AIA, writing-down allowances and full expensing where they fit, carry the pool balances forward year to year, and feed the result straight into your annual accounts and CT600 — pro-rated automatically for short accounting periods.
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