Business Energy Glossary
What is SOQ (Supply Offtake Quantity) in gas?
Supply Offtake Quantity, almost always shortened to SOQ, is the maximum daily volume of gas a UK supply point is permitted to take from the network in any single gas day, expressed in kWh per day. SOQ is the gas equivalent of Authorised Supply Capacity on the electricity side. It is set by the Gas Distribution Network when the supply is connected and forms the basis for daily capacity charges on larger gas supplies, particularly daily metered sites.
For small and mid-sized gas supplies, SOQ is largely invisible to the customer because the daily volumes never approach the limit. For larger industrial and commercial gas users, SOQ matters because it drives daily capacity charges and constrains the maximum daily consumption the site can take. Sites approaching their SOQ may need to apply for an increase.
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What SOQ measures
SOQ is the maximum daily quantity of gas (in kWh) a supply point is contracted to take from the network in any single gas day (06:00 to 06:00 the following morning). The figure reflects the peak daily consumption the supply is sized for.
For most non-daily-metered sites (under 58,600,000 kWh AQ), SOQ is administrative and rarely tested because daily volumes do not approach the limit. For daily metered sites, SOQ matters because it caps the daily volume and triggers daily capacity charges.
How SOQ is set
SOQ is set when the supply is first energised:
- The customer expected peak daily consumption is calculated, including any seasonal variation.
- A safety margin is added (typically 10 to 20 per cent) to allow for growth and cold winter peaks.
- The GDN approves the SOQ based on local network capacity.
For most sites, SOQ stays constant for the life of the connection unless the customer applies for a change.
SOQ vs Annual Quantity
| Property | SOQ | AQ |
|---|---|---|
| Period covered | Single day | Whole year |
| Units | kWh per day | kWh per year |
| What it controls | Maximum daily offtake | Pricing bands and metering classification |
| Updated | By customer application | Annually (1 October) by Xoserve |
| Charged on | Daily capacity charge (DM sites) | Implicit in standing charge and unit rate |
Both numbers describe gas consumption but at different time scales. AQ drives pricing structures; SOQ caps daily delivery.
How SOQ affects bills
For daily metered sites:
- The supplier charges a daily capacity rate per kWh of SOQ.
- The charge applies every day regardless of actual consumption.
- Higher SOQ means higher daily capacity charges.
For non-daily-metered sites, SOQ does not directly appear on bills. Standing charges are based on AQ band rather than SOQ. The SOQ exists but is not a billing parameter.
How to increase SOQ
If the site needs higher daily capacity (typically because of growth or new equipment):
- Apply through the supplier to the GDN.
- The GDN assesses local network capacity at the supply point.
- For simple administrative changes, the new SOQ takes effect within 4 to 6 weeks.
- Where network reinforcement is needed, the GDN quotes the cost and lead time. Reinforcement can take 6 months and require a customer capital contribution.
Reducing SOQ where the original allocation was generous is also possible and reduces daily capacity charges. The application process is similar.
Consequences of exceeding SOQ
If a site exceeds its SOQ in any gas day, the supplier and the GDN can:
- Charge an excess offtake fee for the excess volume.
- Notify the customer that the SOQ needs increasing.
- In persistent breach cases, require the customer to apply for a higher SOQ or reduce consumption.
SOQ breaches are uncommon because the safety margin built into the original SOQ usually accommodates short-term peaks. Persistent breaches indicate the site has materially outgrown its capacity allocation.
SOQ (Supply Offtake Quantity) in gas FAQs
What is SOQ in gas?
Supply Offtake Quantity: the maximum daily volume of gas a UK supply point is permitted to take from the network, expressed in kWh per day. Set by the GDN and used as the basis for daily capacity charges on larger gas supplies.
How is SOQ different from AQ?
SOQ is the maximum daily volume (kWh per day). AQ is the annual consumption estimate (kWh per year). Both relate to gas consumption but at different time scales and for different commercial purposes.
Does SOQ appear on my gas bill?
On daily metered (DM) gas supplies, yes, through the daily capacity charge. On non-daily-metered (NDM) supplies, no, because standing charges are based on AQ band rather than SOQ.
How do I find my SOQ?
On the gas bill for DM sites, or from the supplier on request for any site. The SOQ is recorded in the Xoserve central database against the MPRN.
Can I change my SOQ?
Yes. Apply through the supplier to the GDN. Simple administrative increases or decreases take 4 to 6 weeks. Larger increases requiring network reinforcement can take 6 months and require a capital contribution.
What happens if I exceed my SOQ?
The supplier or GDN may charge an excess offtake fee for the excess volume and notify the customer that the SOQ needs increasing. Persistent breaches indicate the site has outgrown its capacity allocation.
Why does SOQ exist?
To ensure the gas network can support the maximum daily demand of each supply point. The GDN sizes its network to handle the aggregate SOQs of connected customers.
Is SOQ the same as MIC for electricity?
Conceptually similar but for different fuels and time scales. SOQ caps daily gas offtake; MIC (Maximum Import Capacity, also known as ASC) caps half-hourly electricity demand. Both are capacity allocations charged on a daily basis.