Can your business claim capital allowances for solar panels?

Business solar panels are special rate expenditure under HMRC guidance [S1]. Eligible expenditure may qualify for annual investment allowance, whose standard limit is £1 million [S2]. Companies may instead qualify for the special rate first-year allowance, subject to its conditions. These are deductions from taxable profits, not installation grants or cash refunds. Checked October 2026.

Last checked 16 October 2026

Do solar panels qualify for capital allowances?

HMRC specifically classifies expenditure on solar panels as special rate expenditure [S1]. That classification matters because a solar installation should not automatically be advertised as qualifying for company full expensing.

Capital allowances reduce profits subject to tax [S4]. They do not mean that the government pays the invoice. A deduction’s cash value depends on the claimant’s tax position and when relief can be used. Check with your accountant before putting a tax benefit into a project budget.

Keep installation economics separate. Start with the commercial solar cost guide and compare generation, daytime consumption and export value. An allowance cannot establish whether a roof is suitable or whether the electricity will be useful to your business.

Can you claim annual investment allowance on solar panels?

Special rate plant may qualify for annual investment allowance (AIA), as HMRC’s company guidance confirms [S3]. The standard AIA limit is £1 million, with adjustments for shorter or longer accounting periods and sharing rules for related businesses [S2].

Look at the business’s other qualifying investment before allocating AIA to solar. Machinery, fit-out and other projects may use the same allowance. The relevant figure is your available allowance, not the amount printed in a solar sales proposal.

The table summarises HMRC’s routes, not an instruction to select one [S2], [S3], [S4]. Ask your accountant to explain the timing and disposal implications in your circumstances. Reliefs cannot be stacked over the same expenditure to claim more than its eligible cost.

Do solar panels qualify for full expensing or first-year allowances?

Full expensing applies to qualifying main rate plant. HMRC’s solar manual places solar panels in the special rate category [S1]. Company guidance instead describes a 50% first-year allowance for qualifying new and unused special rate plant, with the balance entering the special rate pool in the following accounting period [S3].

That distinction is easy to miss when a quote says only that equipment is “tax deductible”. Ask which allowance, which expenditure and which accounting period the claim assumes.

Do not apply the panel classification automatically to every item in a combined project. Request separate prices for panels, power conversion equipment, battery storage, charging equipment and building work. Give the itemised scope to your accountant for classification rather than assigning every component the same relief.

For a combined installation, read chargepoint capital allowances as a separate rule set. This guide does not provide a tax classification for every battery or roof component.

What does the allowance calculation look like?

This is an illustration, not a quote. Assume £60,000 of expenditure has already been confirmed as qualifying solar plant. The amount is an arbitrary input, not an installed price benchmark. Exclude grants, VAT questions, other equipment and tax losses from this simplified comparison.

The AIA calculation is eligible cost capped by the allowance allocated. The special rate first-year calculation is £60,000 × 50% = £30,000, assuming all conditions are satisfied [S2], [S3]. The remaining amount’s timing and treatment depend on the route selected. This table does not model mixed claims.

To estimate the tax effect, your accountant applies the relevant tax calculation to taxable profits before and after the deduction. Do not describe a £60,000 deduction as £60,000 cash back. Do not subtract it from capital cost as though it were a grant.

A project appraisal should show the operating case before tax, then a separate tax cash-flow adjustment when it can actually be used. Read solar payback before comparing a cash purchase with a third-party-funded arrangement.

How do fully funded, part funded and self funded affect the claim?

Under fully funded arrangements, the provider pays for, owns and operates the equipment. Your roof rights or electricity purchase commitments do not mean your business incurred the provider’s equipment expenditure. Establish the asset owner and claimant from the agreement.

Part funded means shared upfront cost, with ownership and benefits set by contract. A contribution is not itself proof that you can claim on the entire installation. HMRC has rules for contributions towards expenditure [S6]. Have your accountant review who incurs each cost and how any support affects the claim.

With self funded solar, your business pays for the installation and uses or sells its output. Your accountant still needs to check the qualifying activity, expenditure and relief conditions. Compare these structures in buying solar versus a power purchase agreement.

Ask your solicitor to review roof access, lease length, removal, maintenance and obligations if your premises are sold. Include downtime during roof repairs in your commercial comparison rather than treating tax relief as the only deciding factor.

Are solar grants the same as capital allowances?

No. A grant contributes towards project expenditure; an allowance changes the calculation of taxable profits [S4], [S6]. Do not assume a named local grant is open or that a project qualifies without checking its current terms.

HMRC’s contribution rules can affect the amount eligible for allowances [S6]. Supply your accountant with grant award letters and third-party contribution agreements. Keep the grant cash flow and the tax calculation separate so they are not counted twice.

What should you do next?

HMRC directs claims through the relevant tax return [S5]. Prepare the itemised quote, contract, ownership terms, proposed payment dates and your business’s other equipment investment plans. Ask your accountant to confirm the claim route and timing before committing.

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