2026 Update: PSDS & IETF closed. AIA gives 100% year-one relief on solar. 2026 active stack still delivers 40–60% effective subsidy. See 2026 grants →

IETF (closed July 2025) · · 14 min read

IETF Phase 3 Guide | Closure Status & What's Next 2026

A record of the IETF: last Phase 3 window closed 19 April 2024, fund closed July 2025, no successor. What to use instead.

The Industrial Energy Transformation Fund (IETF) is closed. This page is kept as a short record of what it was, because many guides still describe it as open.

What happened

  • The last Phase 3 application window (Spring 2024) shut on 19 April 2024.
  • A GOV.UK update on 3 July 2025, after the 2025 Spending Review, said the fund would not be extended and the planned second Phase 3 window was cancelled. GOV.UK states that no successor fund is planned.
  • Only grants already awarded continue; those projects finish by 31 March 2028. No new IETF money can be applied for or counted toward a project today.

What it did and did not fund

The closed IETF scored industrial energy-efficiency and fuel-switching projects at eligible industrial sites (manufacturing SIC codes, data centres and a few other activities). Solar PV and other electricity generation were never eligible, and batteries were not an eligible technology. Heat pumps qualified only for industrial process heat or cooling at eligible sites.

Scotland, Wales and Northern Ireland

The Scottish Industrial Energy Transformation Fund (SIETF) was a separate Scottish Government scheme. Its fourth and last call closed in March 2025 and no new call has been announced. It also never funded solar PV.

What to use instead

For a commercial solar project the money now comes from the Annual Investment Allowance (100% on up to £1m a year; solar is special-rate expenditure, so the 50% special-rate first-year allowance covers spend above that), Smart Export Guarantee income, a PPA or asset finance. See the Annual Investment Allowance guide and the grants hub for what is open today.

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Grants & Funding

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Tax & Finance

AIA vs Solar Grants 2026 | Why Tax Relief Often Wins

Solar PV is special-rate plant, so Full Expensing does not apply — AIA gives 100% year-one relief, worth ~25% of capex.

Funding by asset class

The allowance depends on the asset, and most pages on this topic get it the wrong way round. Solar PV is special-rate expenditure (HMRC Capital Allowances Manual CA22335), so the 100% year-one route is the Annual Investment Allowance — Full Expensing is a main-rate measure and does not reach it. Battery storage, EV charging and heat pumps are Heat pumps for space or water heating are special-rate: AIA, then the 50% FYA. Standalone batteries are probably main-rate (full expensing for companies), but HMRC has no specific guidance; confirm with your adviser.

Free funding review

Find out which 2026 schemes your site actually qualifies for

What you get
  • 1. A short written funding note naming every scheme your site qualifies for in 2026 — and the ones it does not.
  • 2. Indicative system size and a capex band for your roof.
  • 3. Year-one tax treatment per asset in £ — solar is special-rate expenditure, so the route is the Annual Investment Allowance; heat pumps for building heating are also special-rate integral features, and standalone battery storage is probably main-rate plant (HMRC has no specific guidance, so confirm with your adviser). Most pages get this the wrong way round.
  • 4. Projected SEG export revenue at current rates.
  • 5. Any red-flag eligibility or DNO issues we can see up front.

Covers solar PV, battery storage, EV charging and commercial heat pumps — separately or as one bundled project. If your project is a heat pump or a battery rather than a roof, say so in the message box and the note is written against that asset instead.

What we will not do
  • · We do not pass your details to multiple installers.
  • · We do not run a lead auction, and your phone number is optional.
  • · No marketing lists, no unsolicited calls.
  • · We are an independent funding information service — not an installer.

Five questions. They are the eligibility test itself — scheme eligibility in 2026 turns on sector, tenure, site size and spend, so we cannot shortlist anything without them.

We reply from funding@commercialsolargrants.co.uk. A phone number is not required.