Grants & Tax

Can I claim tax relief on commercial solar panels?

Yes — UK businesses can claim 100% Annual Investment Allowance (AIA) on commercial solar PV, deducting the full capex from taxable profits in year one (up to £1m/year). For a profitable limited company at 25% corporation tax, that's effectively a 25% discount on the install. Capital allowances rules and timing matter — verify with your accountant before signing.

Yes — UK businesses can claim 100% Annual Investment Allowance (AIA) on commercial solar PV. AIA lets you deduct the full capex from taxable profits in the year of purchase, up to £1 million per accounting period. For a profitable limited company at the current 25% corporation tax rate, that’s a 25% effective discount on the install funded by HMRC. An £80,000 installation costs you £60,000 net of tax. Solar qualifies as plant and machinery for AIA purposes (HMRC manual CA22320), the same category as factory equipment, vans, and computers. Speak to your accountant before signing — timing of the contract date and commissioning matter.

How AIA actually works on solar

AIA is part of the UK capital allowances regime. The key rules:

  1. Eligible expenditure: capex on plant and machinery for use in your business. Solar PV systems qualify in full, including panels, inverters, mounting, cabling, scaffolding, and DNO connection costs. Battery storage also qualifies.
  2. £1m annual cap: each business can claim AIA up to £1 million per accounting period. Almost no SME install hits this cap.
  3. Year of claim: the year you “incur the expenditure” — generally when the installer raises the invoice and the system is operational. Get the timing right around your year-end.
  4. Group rules: companies in a group share a single £1m AIA allowance — relevant only for larger structures.

Worked tax relief example

A limited company spending £92,000 on a 100 kW solar install during its accounting period (year ending 31 March 2026):

  • Headline cost: £92,000
  • Add: 20% VAT = £18,400 (recoverable in the next VAT return for VAT-registered businesses)
  • AIA claim: £92,000 deducted from taxable profits
  • Corporation tax saving (at 25%): £23,000
  • Effective net cost: £92,000 - £23,000 = £69,000

If you don’t have £92,000 of taxable profit in that year, the unused AIA can’t be carried forward as AIA — it converts to writing-down allowances at 18%/year. Plan AIA claims to coincide with profitable years.

Other tax considerations

VAT recoverability

VAT-registered businesses recover the 20% VAT on commercial solar through their normal VAT return — neutral cashflow impact within a quarter. Non-VAT-registered businesses absorb the 20% as a real cost.

Business rates

Solar PV does not, in 2026, increase the rateable value of a commercial property. The Valuation Office Agency excludes plant and machinery (including PV) from rating valuations under the Plant and Machinery (Valuation for Rating) Order. This was a meaningful concern pre-2017 — no longer.

Capital Gains Tax on sale

If you sell the building with the system installed, the disposal value of the PV is part of the property sale. AIA previously claimed may be subject to balancing charges if disposed within the asset life. Get accountancy advice for any sale.

Sole traders and partnerships

Unincorporated businesses on cash basis can deduct solar capex in the year of purchase under different rules but at the same effective rate. Partnerships split the relief in proportion to profit shares.

Common misconceptions about solar tax relief

“It’s a grant” — no. AIA is a tax deduction, not a grant. You claim it via your corporation tax return. The “saving” comes through reduced tax bill, not a cheque from HMRC.

“It only applies to limited companies” — no. Sole traders, partnerships, and LLPs can also claim, just through different parts of the tax system (cash-basis expensing, AIA on partnership returns).

“You can claim it twice if you re-finance” — no. AIA applies once at purchase. If you re-finance later, the lender may take the benefit of the asset but the original AIA is unaffected.

“There’s a special enhanced allowance for green tech” — partly. The Super-Deduction (130% relief) ran 2021-2023 and has ended. Full Expensing (100%, equivalent to AIA in effect) is now permanent for limited companies, separate from AIA. Either route works; your accountant will pick the optimal one.

Next steps

For a written quote modelled with AIA tax relief, contact us. See our grants and funding page and cost overview. Related FAQs: grants overview, VAT rules, finance options. Always verify capital allowances with your accountant before contracting.

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