Green Gas Levy (GGL): rates, underlying variables, mutualisation threshold and de minimis for the 2025-2026 financial year
Updated 20 December 2024
Applies to England, Scotland and Wales
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The Department for Energy Security and Net Zero (DESNZ) has a regulatory duty under Regulation 39(2) of the Green Gas Support Scheme Regulations 2021 to publish the Green Gas Levy (GGL) rate for each scheme year (beginning 1 April) by 31 December of the preceding year.
GGL rates
The GGL rate for the 2025-2026 scheme year (1 April 2025 to 31 March 2026)
- 0.821p per meter per day, equivalent to £3.00 per meter over the financial year
Underlying variables
In line with the regulations, the 2025-2026 levy rate has been calculated based on the following variables:
| Variable | |
|---|---|
| A – Adjustment factor | 1.00988 |
| SB – Projected scheme expenditure * | £86,316,999 |
| SD – Forecast scheme year end surplus | £20,850,794 |
| AA – Ofgem’s total forecasted administration costs | £3,925,000 |
| TY – True-up from scheme year before last | -£8,157,537 |
| TD – Year end deficit from scheme year before last | £0 |
| QL – Quarterly lag uplift | £14,320,754 |
| H - Headroom | £2,193,953 |
| I – Interest accrued on levy funds held in Ofgem bank account | £1,386,907 |
| Ofgem’s estimated administration costs for carrying out a mutualisation process** | £11,393 |
*This corresponds to the GGSS Overall Scheme Expenditure Budget, published on the GGSS: Budget Management page.
**Note that Ofgem’s administration costs for carrying out the mutualisation process is the same value as the mutualisation threshold.
Mutualisation threshold
The mutualisation threshold is any levy shortfall above £11,393.
De minimis
A de minimis for the GGL was introduced on 1 December 2023 through the Green Gas Support Scheme (Amendment) Regulations 2023.
Obligations for some payments and provision of credit cover for amounts under the de minimis are automatically disapplied. The provision also suspends some of Ofgem’s notification obligations relating to payments below the de minimis level.
The de minimis applies to quarterly levy payments, credit cover requirements, distribution of interest on levy credit payments, repayment of levy credit payments, backdated levy payments for formerly provisionally exempt suppliers, payments due to or from a former scheme supplier, and mutualisation payments.
The de minimis for a scheme year is announced by the preceding 31 December and is subject to a statutory maximum level of £200, adjusted by the percentage increase or decrease in the consumer prices index for the period beginning with 1 January 2024 and ending with 31 October immediately preceding the scheme year.
The GGL de minimis for 2025-2026 is £50.