From 1 April 2026, the Non‑Domestic Rating (Renewable Energy Projects) (Amendment) Regulations 2026 introduce a ‘relevant multiplier ratio’ into the 2013 scheme so the amounts billing authorities may disregard for designated renewable energy hereditaments are insulated from changes to business rates multipliers. The government’s stated aim is that retention for these projects should reflect the position that would have applied without the additional multipliers. (gov.uk)
Under the Renewable Energy Projects scheme set out in the 2013 Regulations, the authority that determined the planning application can retain growth from specified classes of renewable hereditament outside the wider reset of the Business Rates Retention System. In its reset paper, the government confirms that renewable energy arrangements remain exempt from the reset, but acknowledges that the new multipliers would otherwise distort the disregarded amounts without adjustment. (gov.uk)
The legislative driver is the Non‑Domestic Rating (Multipliers and Private Schools) Act 2025, which enables additional multipliers from April 2026. Official Explanatory Notes describe a High Value Multiplier for hereditaments with a rateable value of £500,000 or more and two lower Retail, Hospitality and Leisure multipliers, supplementing the existing standard and small business multipliers. (legislation.gov.uk)
In practical terms, the ‘relevant multiplier ratio’ compares the multiplier actually applied to a hereditament on a given day with the baseline multiplier for that class (the small business or the standard multiplier). Where a property sits on the High Value Multiplier, the ratio is greater than one; where a Retail, Hospitality and Leisure multiplier applies, it is less than one. Scaling the daily non‑domestic rating income by this ratio removes the effect of the supplement or discount from the disregard calculation without changing the bill issued to the ratepayer.
The Regulations implement this by inserting the ratio into the definition of non‑domestic rating income and carrying it through the daily disregard calculations for classes A to F. For years ending on or before 31 March 2026, calculations remain as before; from 2026‑27 the scaled approach applies across the scheme so that all six classes are treated consistently.
For billing authorities the operational impact is largely data and reporting. Authorities will need, for each qualifying hereditament and for each day, to confirm which multiplier applied so the ratio can be applied to that day’s income. The government indicates NNDR forms and local authority software are being updated for 2026‑27 to accommodate the reset and additional multipliers, and has published NNDR1 guidance to support preparations. (gov.uk)
Policy intent is stability for host authorities. Government states that the impact of the new multipliers on income retained under renewable energy projects will be neutralised so far as practicable, meaning authorities should neither gain from the High Value Multiplier nor lose where an RHL multiplier applies. (gov.uk)
Baseline mechanics for classes B and C are unchanged. The initial baselines are expressed as rateable values and continue to adjust only at revaluation; as the government notes, no baseline change is needed to accommodate the introduction of additional multipliers. (gov.uk)
An illustration follows the policy logic. If a high‑value renewable hereditament is billed on the High Value Multiplier, its daily non‑domestic rating income would, absent adjustment, increase by the HVM supplement; the ratio therefore increases the disregarded amount by the same proportion so the retained position matches the pre‑2026 structure. Conversely, if an eligible hereditament is billed on a lower RHL multiplier, the ratio reduces the disregard to offset the discount, again leaving the authority’s underlying retention unchanged relative to the former two‑multiplier system. (gov.uk)
Multiplier levels for 2026‑27 will be set at Autumn Budget 2025. Ahead of 1 April 2026, authorities should confirm the correct multiplier classification for each renewable hereditament and ensure internal models apply the ratio in daily calculations; the policy baseline is that retention continues to track the standard or small business multipliers rather than the new HVM/RHL structure. (gov.uk)