If you're deciding between booking solar now or waiting a year or two, the most concrete change to factor in is the VAT shift on 1 April 2027. Here's what it does to typical install pricing. The key point: VAT goes back to 5%, not 20%.
What ends, what doesn't
On 1 April 2027, the 0% rate on qualifying domestic energy-saving materials reverts to 5%. The full 20% rate does not return. Solar, batteries, heat pumps and insulation all stay in the reduced-rate bracket. They lose the temporary 0% boost.
Like-for-like cost comparison
Identical 2026-spec installs, priced before and after the VAT change. These assume install prices stay flat, which they may not (panel prices could keep softening, or installer costs could rise). Treat them as the VAT-only difference:
- 4kW solar only: £7,500 (today) → £7,875 (April 2027)
- 4kW + 10kWh battery: £11,500 → £12,075
- 6kW + 10kWh + smart EV charger: £14,500 → ~£15,100 (charger separately rated)
- Heat pump + 8kW solar: £20,000 → £21,000
A few hundred to roughly a thousand pounds, depending on system size. Significant for any household, but not the difference between a sensible decision and a foolish one.
Don't fall for the lock-in trick
HMRC sets VAT by the tax point: the install commissioning date, not the contract or deposit date. Some installers pitch a "book now to lock in the 0% rate" deal where the install lands months into the 5% rate. You'll be charged the higher rate. The only way to bank the 0% rate is to have the system commissioned by 31 March 2027.
The practical decision window
Reputable installers typically run 8–12 weeks from design sign-off to commissioned install. Working back from 31 March 2027, a contract signed by mid-January 2027 is the latest safe window. Slots tend to fill sharply in Q1 of any year, so aim to decide by late autumn 2026 if you want the 0% rate.
What this means
If solar is on the cards within the next 12–18 months, the VAT change is a good reason to commit sooner. If you're still 50/50 on whether solar is right for your home, £500 of VAT shouldn't push you into a decision. Get the system designed properly first; think about timing second.
