Can I Claim Solar Panels as a Business Expense?

Yes — but not as a day-to-day running cost. A commercial solar installation is capital expenditure, so it does not go through your profit-and-loss account the way the electricity bill or a roof repair does. Instead, it is relieved through the capital allowances regime, and the practical effect is that most businesses can write off the full cost in the year of purchase using the Annual Investment Allowance (AIA), which covers up to £1 million of qualifying spend each year. The distinction matters because it changes how the relief appears in your accounts, who can claim it, and how much cash it actually returns. This is a tax point, so take professional advice from your accountant before you commit to numbers — the position below is the general 2026 framework, not advice on your specific company.

Expense versus capital — why the wording matters

When people ask whether they can “claim solar panels as a business expense”, they usually mean: can I knock the cost off my taxable profit? The answer is yes, but the route is capital allowances, not revenue deduction.

A revenue expense is something consumed in the period — your monthly electricity, insurance, repairs, consumables. You deduct the whole amount against that year’s profit automatically. A solar array is different: it is a long-life asset that earns you savings for 25 to 30 years, so HMRC treats the purchase as capital. Capital items get tax relief through capital allowances rather than as a straight expense line.

The good news for cash flow is that, since the AIA covers £1m of annual investment, a typical commercial system priced at roughly £700–£1,100 per kWp — say £82,000–£110,000 for a 100kWp roof, or £150,000–£240,000 for a 250kWp system — usually sits comfortably inside the allowance. So the outcome is much the same as expensing it: you can claim the full cost against taxable profit in year one. The mechanism is just different, and that mechanism dictates who qualifies and how the figure is calculated.

How solar is classified: the special rate pool

Solar PV does not fall into the “main rate” pool of plant and machinery. HMRC classifies solar panels as an integral feature, which puts them in the special rate pool. Left in that pool, special-rate assets attract writing-down allowances at just 6% per year on a reducing balance — slow relief that drags on for decades.

The AIA is what rescues you from that slow drip. The AIA can be set against special-rate expenditure, so you can claim 100% of the cost in year one up to the £1m limit, instead of chipping away at 6% a year. For the overwhelming majority of single-site commercial installations, the AIA is the route that turns a 6%-a-year trickle into a one-year write-off.

If your total qualifying capital spend in a year exceeds £1m, anything above the cap falls back into the special rate pool and is relieved at 6% on the reducing balance thereafter. Most owner-occupiers and SMEs never hit that ceiling on a solar project alone.

What about full expensing — does solar qualify?

You may have read about full expensing, the relief that lets companies deduct 100% of qualifying plant and machinery in year one with no upper limit. It is worth being precise here, because solar is treated differently.

Full expensing applies at 100% to main-rate assets. Because solar sits in the special rate pool, it does not get 100% full expensing. Special-rate assets instead qualify for the 50% first-year allowance (FYA) under the full-expensing rules — you relieve half the cost in year one and the balance enters the special rate pool at 6%.

So you have two routes for a solar purchase, and they are mutually exclusive on the same expenditure:

• AIA — 100% relief in year one, up to the £1m annual cap. Available to companies, sole traders and partnerships.
• 50% FYA — 50% in year one, remainder at 6%, no cap, but companies only.

For almost every commercial solar project under £1m, the AIA wins outright: it gives you the full deduction in year one rather than half. The 50% FYA only becomes relevant for very large programmes of capital spend that blow through the AIA ceiling, and only for limited companies. Your accountant will pick the optimal route, and there are important exclusions to watch — assets bought specifically to lease to someone else generally cannot use the AIA or FYA, which is the trap landlords fall into (more on that below).

What the relief is actually worth in cash

This is where honest expectations matter. A capital allowance reduces your taxable profit — it is not a pound-for-pound discount on the system. The cash benefit is the relief multiplied by your tax rate.

Take a 100kWp system at £95,000 with the full AIA claimed:

The £23,750 is the reduction in your corporation tax bill, not a cheque from HMRC. A sole trader or partnership relieves it against income tax at their marginal rate instead, so the cash value moves with the rate that applies to them. If your business made a loss, the allowance can create or increase that loss, with separate rules on how losses are carried — another reason this needs a qualified eye.

The headline is straightforward: you can write the whole system off against profit in year one, but the money back in your pocket equals roughly the cost times your tax rate, not the full cost.

The landlord problem: assets bought to lease

If you own the building and use it yourself — an owner-occupier — you claim the allowances against your own trading profits and keep 100% of the savings. Clean and simple.

Landlords face a wrinkle. Where solar is installed on a property let to a tenant and the kit is effectively bought to be used by someone leasing the premises, the AIA and first-year allowances are typically not available. Landlords are usually left claiming the slower 6% writing-down allowance in the special rate pool. The way the system is structured commercially — common-parts supply, a tenant PPA, a green lease, or selling the roof — affects who consumes the power, who owns the asset, and therefore what allowances can be claimed and by whom. This is a genuinely technical area where the legal structure drives the tax outcome, so landlords in particular should map the structure with an accountant before installation. Our guide to capital allowances and funding for owners walks through the owner-occupier and landlord positions in more detail.

Other tax and value points worth knowing

A few related facts round out the picture, and each one should be confirmed for your circumstances:

• VAT — there has been a 0% VAT rate on qualifying solar installations since April 2022, so there is generally no VAT to reclaim because none is charged on the install in the first place.
• Business rates — solar and co-located battery storage used for on-site generation are exempt from business rates through to 2035, so adding panels should not push up your rateable value.
• The return is mostly in the energy bill, not the tax — capital allowances are a meaningful sweetener, but the dominant driver of payback (typically 4–8 years) is self-consumption: using the power you generate instead of buying it from the grid. Exported power earns far less under the Smart Export Guarantee (around 12–16p/kWh) than you save by consuming it (around 24–28p/kWh).

Grants and funded routes can change the capital position too — what you actually pay, and therefore what you can claim, depends on how the project is financed. See grants and funding for the current landscape, and bear in mind that finance leases and operating leases interact with capital allowances differently from an outright purchase.

The short answer, and the next step

You can effectively claim a commercial solar installation against tax — through capital allowances, with the AIA letting most businesses write off 100% of the cost in year one — but it is capital relief, not a simple expense, the cash benefit equals the relief times your tax rate, and landlords buying kit to lease are usually restricted to the slower 6% allowance. Because every one of those points turns on your structure, profits and rate, this is a matter to confirm with your accountant rather than read off a blog. If you want a costed system to put those numbers against, request a quote and we will scope a design and price for your roof so your accountant has real figures to model the relief on.