For tax-paying care home companies, capital allowances turn a £45,000 solar install into an effective £33,750 outlay — a 25% discount at the main corporation tax rate. The two allowances that matter for solar PV are the Annual Investment Allowance (AIA) and the 50% First Year Allowance (FYA). This page explains how both work, when each applies, and the worked examples that matter for care home decision-makers.
Annual Investment Allowance (AIA)
The Annual Investment Allowance provides 100% first-year capital relief on qualifying plant and machinery up to £1 million per company per year. Solar PV qualifies as general-pool plant. For a limited company paying 25% corporation tax (main rate), every £1,000 of AIA-claimed capex reduces the corporation tax bill by £250.
AIA worked example: £45,000 system
- Solar install capex: £45,000
- AIA claim: £45,000 (within £1m annual limit)
- Tax relief at 25% main rate: £11,250 saved
- Effective net capex: £33,750
- Year-1 annual saving: £8,250
- Simple payback on effective capex: 4.1 years
50% First Year Allowance
For limited companies (not partnerships or sole traders) spending more than £1m on qualifying plant in a single tax year, the 50% First Year Allowance applies to special-rate pool expenditure above the AIA cap. Half the spend gets immediate tax relief; the other half goes into the special-rate pool at 6% writing-down allowance per year.
FYA was originally announced as a temporary measure in Spring Budget 2023; the 2026 Autumn Budget confirmed FYA as permanent from April 2026. This matters for large care groups planning multi-year capital programmes — the tax shield is now reliable for planning purposes.
FYA worked example: £2.4m portfolio rollout
- Group operator invests £2.4m in solar across 22 sites in tax year
- AIA on first £1m: full relief, £250,000 tax saved at 25%
- FYA on remaining £1.4m: 50% × £1.4m = £700,000 immediate relief, £175,000 tax saved
- Remaining £700,000 enters special-rate pool at 6% WDA = £42,000 tax relief per year continuing
- Year-1 total tax shield: £425,000 on £2.4m capex = 17.7% effective discount
- Year-2 onwards: ~£42,000/year continuing WDA shield
Eligibility — who claims what
| Operator type | AIA | 50% FYA | Notes |
|---|---|---|---|
| Limited company (single home) | ✓ | ✓ (above £1m) | Most common care home operator structure |
| Limited company (group) | ✓ | ✓ | Single £1m AIA per group, not per home |
| Partnership / LLP | ✓ | ✗ | AIA only — no FYA for partnerships |
| Sole trader | ✓ | ✗ | AIA only — claimed against income tax |
| Charity | Limited | ✗ | Only via trading subsidiary — main charity not tax-paying |
| Housing association | Varies | Varies | Depends on corporate structure; consult auditors |
What qualifies as solar plant
HMRC categorises solar PV as general-pool plant qualifying for AIA. The qualifying capex includes:
- PV panels
- Inverters (string, central, microinverters)
- Mounting systems (clamps, rails, ballast, ground-mount frames)
- DC and AC cabling
- Combiner boxes and DC isolators
- Monitoring equipment
- Battery storage (separately categorised as special-rate pool from April 2023)
- Installation and commissioning labour (included in capex)
Not qualifying: design fees (typically expensed), planning fees (expensed), and post-commissioning maintenance (operating expense).
How to claim
Capital allowance claims are made in the year of acquisition (when the asset is brought into use, not when the contract is signed). For most care home installs commissioned during a tax year, that means the year in which the system is commissioned and producing electricity.
We provide the documentation your accountant needs at handover:
- Itemised capex breakdown separating qualifying plant from non-qualifying expenditure
- Commissioning date confirmation
- Depreciation schedule (for accounting, not tax)
- MCS certification (relevant for some advanced relief regimes)
The claim is made on the corporation tax return for the period in which the asset is acquired. There's no separate application — capital allowances are a self-assessment claim.
Stacking capital allowances with grants
An important nuance: capital allowances are not available on the grant-funded portion of an install. If SHDF Wave 2.2 funds 50% of a sheltered scheme install, AIA is only available on the operator-funded 50%. This usually still leaves a substantial claim, but worth modelling carefully for grant-eligible projects.
Group considerations
For care home groups, AIA is a single £1m allowance shared across the group (not £1m per company). For groups planning rollouts above £1m in a single tax year, the AIA + 50% FYA combination becomes critical. We model the optimum timing of capital spend across tax years to maximise allowance utilisation.
Common pitfalls
- Claiming AIA before commissioning. The asset must be in use to claim. Signing a contract in March doesn't qualify for a March year-end tax claim if commissioning happens in April.
- Missing the grant deduction. Grant-funded portions can't be claimed. Net the grant before claiming AIA.
- Treating PPA payments as capex. PPA tariff payments are operating expense, not capex — no AIA. Only owned systems qualify.
- Overlooking battery as special-rate pool. Battery storage went to special-rate pool from April 2023. Different writing-down rate (6% vs 18%) if AIA exceeded — but AIA itself is unchanged.
For the full funding stack — capital allowances combined with grants, finance, and business rates exemption — see grants and funding for care home solar.
AIA group considerations and the connected-companies rule
For care home groups using multiple corporate entities (common for asset-protection or tax-planning reasons), the AIA is a single £1m allowance shared across the group of connected companies, not £1m per company. HMRC defines connected companies under CTA 2010 s.451 — broadly, companies under common control of the same persons. This catches the typical "trading company + property company" structure many family-owned care operators use.
The single AIA must be allocated across the group's qualifying expenditure. For groups rolling out solar across multiple sites in a tax year, the AIA allocation strategy matters: you can allocate the £1m to whichever group company best benefits from the tax shield, but you can't claim £1m per company. Plan the allocation with your tax adviser before the year-end.
Loss-making care home operators and AIA
If your care home company is loss-making in the year of acquisition (genuinely common for new homes or homes in turnaround), AIA still applies — but the relief is captured against trading losses rather than reducing current-year tax. The resulting enhanced loss can be carried forward indefinitely against future trading profits under current rules. This effectively defers the tax benefit; it does not eliminate it.
For groups with a mix of profit-making and loss-making companies, group relief allows the loss-making company's enhanced loss to be surrendered to a profit-making group member, capturing the cash-flow benefit immediately. Worth modelling carefully — the cash-flow timing of AIA can shift by 1–3 years depending on group structure.
Capital allowances vs depreciation
Capital allowances (the tax position) and depreciation (the accounting position) are not the same. AIA gives 100% first-year tax relief. Accounting depreciation typically spreads the cost over the asset's useful economic life — typically 25 years for solar PV. The difference creates a "deferred tax liability" on the balance sheet: tax relief is taken upfront, accounting expense spread evenly, so post-tax accounting profit in years 2–25 is lower than cash position would suggest.
This is normal and not a problem — but worth explaining to non-financial directors who see the "depreciation hit" in year 2+ and ask why the savings don't show up in P&L. The savings show up as reduced electricity expense; the depreciation is a non-cash accounting entry; the tax benefit was captured year one.
AIA timing — year-end planning
For care home operators with a tax year-end approaching, the timing of solar commissioning matters. AIA applies in the tax year the asset is brought into use. A system commissioned 28 February falls into the February year-end tax year; the same system commissioned 7 March falls into the next tax year.
For operators with strong taxable profits in the current year, accelerating commissioning to fall within the current tax year may be worth £8,000–£15,000 in time-shifted cashflow on a £45,000 install. For operators in a loss-making position, deferring commissioning to a future profit-making year may give better cash-flow capture — though group relief usually neutralises this consideration.
Combining AIA with grant funding — the netting rule
If your install is part-funded by a grant (SHDF Wave 2.2, LA-administered decarbonisation funding), AIA can only be claimed on the operator-funded portion. HMRC's grant deduction rule reduces the qualifying expenditure pound-for-pound. For a £100k install funded 50% by SHDF, AIA is claimable on the £50k operator portion only.
This is rarely a deal-breaker — the grant + AIA combination still beats either route alone — but it does mean the headline "£100k install with £25k AIA shield" doesn't work where grants are stacked. Plan the math with your accountant before commitment.