Business Energy Glossary
What is non-daily metered (NDM) gas?
Non-daily metered (NDM) gas is the metering arrangement used for most UK business gas supplies. Meter reads are taken periodically (annually, quarterly, or monthly depending on the AQ band) rather than daily. Consumption is distributed across the billing period using a standard profile assumption agreed by the gas industry. NDM is the standard for any site with Annual Quantity below 58,600,000 kWh.
Most UK business gas sites are NDM. The arrangement keeps metering costs low and is sufficient for sites where daily consumption data is not needed for operational or pricing reasons. The trade-off is reduced visibility of when gas is being used and less flexible pricing structures than available on daily metered (DM) supplies.
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What NDM means
Non-daily metered (NDM) gas is the settlement arrangement for most business gas sites, where meters are read periodically and usage is profiled rather than measured daily. It applies to sites below 58.6 million kWh a year and affects how often you get actual rather than estimated bills.
For the full explanation, see Understanding How Business Gas Meters Work.
A non-daily metered gas supply has its consumption measured periodically rather than daily. The meter records cumulative consumption continuously, but the read is captured by the meter reader (manually, by AMR, or by smart meter) on a defined cycle. Between reads, the supplier estimates daily consumption using standard profile assumptions for the AQ band and the customer business type.
NDM is the default arrangement for any supply below 58,600,000 kWh AQ. It accounts for the vast majority of UK gas meters by count.
NDM read frequency
Read frequency depends on the AQ band:
| AQ band | Standard read frequency |
|---|---|
| Under 73,200 kWh | Annual read |
| 73,200 to 293,000 kWh | Quarterly read |
| 293,000 to 58,600,000 kWh | Monthly read |
Between scheduled reads, customer-submitted reads can be accepted. Most suppliers encourage customer reads to reduce the need for estimates. AMR-equipped meters report automatically each month regardless of AQ band.
NDM profile classes
The UK gas industry uses standard profile classes to distribute periodic consumption across days for settlement and billing purposes. The classes:
- End User Category 01 (domestic-equivalent low usage). Heavy winter weighting, low summer usage.
- End User Category 02 (commercial low usage). Similar to 01 but with slightly different weekend patterns.
- End User Category 03 (mid-size commercial). Less seasonal variation than category 02.
- End User Category 04 (large commercial / small industrial). More consistent across the year.
Suppliers and Xoserve allocate a profile to each meter based on AQ and business type. The profile determines how the quarterly or monthly read is distributed across the period for settlement purposes.
NDM metering equipment
NDM meters are simpler than DM:
- Traditional diaphragm or rotary meter. Mechanical or electronic display, manual read.
- Smart meter (SMETS2). Communicates monthly reads to the supplier via the DCC network.
- AMR meter. Equipped with a pulse output and communicating device for automated monthly reads.
No data logger is needed for NDM because daily reads are not required. The simpler equipment is cheaper to install and maintain, reflected in lower meter operation fees.
AMR on NDM supplies
Many NDM sites in the 73,200 to 58,600,000 kWh range are fitted with Automatic Meter Reading equipment that captures monthly reads automatically. AMR provides:
- Consistent monthly reads. No more annual or quarterly estimate-and-correct cycles.
- Reduced bill disputes. Bills are based on actual consumption rather than profile-based estimates.
- Energy management visibility. Monthly data supports consumption monitoring and target setting.
AMR on NDM is not the same as DM. DM requires daily reads to feed daily settlement. AMR captures monthly reads but settlement still happens through profile-based distribution.
NDM vs DM
| Feature | NDM | DM |
|---|---|---|
| Read frequency | Annual, quarterly, or monthly | Daily |
| Settlement | Profile-based assumed daily | Actual daily |
| AQ updates | Annual (1 October) | Quarterly |
| Equipment cost | Lower | Higher (data logger, comms) |
| Pricing options | Fixed and variable | Fixed, market-linked, flexible |
| Suits | SME and standard commercial | Large industrial, sophisticated procurement |
non-daily metered (NDM) gas FAQs
What is non-daily metered gas?
A metering arrangement where meter reads are taken periodically (annually, quarterly, or monthly) rather than daily. Standard for UK business gas supplies below 58,600,000 kWh Annual Quantity.
How often is an NDM gas meter read?
Annual for sites under 73,200 kWh AQ, quarterly for 73,200 to 293,000 kWh, monthly for 293,000 to 58,600,000 kWh. Customer-submitted reads are accepted between scheduled reads.
What is the difference between NDM and DM gas?
NDM reports periodically with consumption distributed using profile assumptions. DM (Daily Metered) reports actual daily consumption. NDM is simpler and cheaper; DM offers more accurate data and more pricing flexibility but costs more to operate.
Can NDM supplies have smart meters?
Yes. Smart meters (SMETS2) on NDM supplies can send readings daily or more often, depending on supplier settings. Smart meter rollout to NDM business sites is part of the wider UK smart meter programme.
What is an NDM profile class?
A standard consumption pattern used to distribute quarterly or monthly NDM reads across days for settlement and billing. Profiles range from heavy-winter domestic-equivalent patterns to flatter year-round industrial patterns.
How accurate are NDM bills?
Bills based on actual reads (manual or AMR) are accurate. Bills based on profile-distributed estimates between reads have some imprecision, corrected when the next actual read is processed. AMR-equipped NDM sites have substantially better billing accuracy than annual-read sites.
What does AMR mean on an NDM supply?
Automatic Meter Reading: equipment that captures monthly reads automatically and transmits them to the supplier. AMR is common on NDM supplies above 73,200 kWh AQ and reduces reliance on estimated bills.
Can I move from NDM to DM?
Yes, if the AQ is between 293,000 and 58,600,000 kWh. The customer requests the change through the supplier; new metering equipment is installed by the Meter Asset Manager. DM provides more pricing options and better data but costs more in metering fees.