The Different Gas Supply Classes

In history, when gas was first starting to become a valued aspect in our homes, Supply Meter Points (SMPs) were made up of two main categories/site types; your Daily Meters and your Non-Daily Meters.

While this is somewhat easy to understand, because the names of each offset clearly explained which process they followed, it became somewhat more complex when these main site types are then divided into four Class Products. These are easily labelled as Class 1, 2 and 3.

Even today, when our council tax band is a google search away, the class product your gas falls into isn’t something we commonly know first hand about our utilities; What is a gas supply class and what does it mean? How do I find out my gas supply class?

It is important to note that the process for each class of meter are different, and all should be treated differently.

Whilst the processes of Class 1 Daily Meters and Class 2 Non-Daily Meters seem similar at first glance, there are some critical distinctions between these classes which will need to be dealt with individually in order to provide accurate billing statements for your home or business.

When it comes to determining your site’s class, there are three different classes. If you use more than 58.6m kWh of electricity a year, then you will be considered Class 1 and cannot change the classification no matter what other criteria is met. The Shipper can choose from one of four possible classes: 2, 3 or 4 if they meet certain requirements for that specific category.

There is, though, a small number of sites without AQs less than the suggested 58.6km that are permitted to be Class 1. These include:

  • Seasonably Large Supply Points
  • SLSP Network Designated Sites
  • Sites which are Interruptible

This table can explain the main processes at a high level and how they may or may not change dependant on these processes.

Process DescriptionProcess for initial AllocationProcess for Energy Balancing closeoutRead Submission TimescalesTypes of Read SubmissionAQ circulationReconciliation
Class 1 – Daily Metered Time Critical ReadingsUses daily readUses daily readBy 11am on GFD+1All reads daily on GFD+1Monthly using Optimum ReadMeter Point level following a site visit or estimate
Class 2 – Daily Metered not Time Critical ReadingsTransporter estimateUses daily readBy end of GFD+1All reads daily by end of GFD+1Monthly using Optimum ReadMeter Point level following a site or estimate
Class 3 – Batched Daily ReadingsAllocation ProfilesAllocation ProfilesDaily reads in batchesAll daily reads in batchesMonthly using Optimum ReadDaily Rec at Meter Point level on receipt of a batch of reads
Class 4 – Periodic ReadingsAllocation ProfilesAllocation ProfilesPeriodic readsPeriodic readsMonthly using Optimum ReadMeter Point level at receipt of read

More about Class 1…

Due to the information mentioned above, Class 1 sites use an AMR Automated Meter Reading or Datalogger Device that is attached to each site of its type. This allows for readings to be collected accurately and remotely each day. They are checked each year (or sooner, where necessary) to ensure that the device is working correctly throughout its time. Allocation and Energy Balancing processes are based primarily on the daily read taken here.

The process of closing out a gas day requires all daily readings to be submitted before 1400 hrs. (Or later  by 1200 hrs, referred to as “best endeavours”) and will only include measurements made within the 5 hour window following this deadline if they are received before GFD+5, with any late submissions being used for reconciliation purposes instead.

There are a handful of aspects taken into account in order to ensure that the file can be submitted. These are listed below, though this list is not exclusive and others may use more, or different processes:

  • The file format must be completed correctly
  • SMP is part of a Shipper portfolio
  • The Meter Serial Number (MSN) matches
  • Energy Tolerance
  •  checks, explained below…
  • Energy Tolerance is based on two things: the number of actual reads and your AQ. Your SOQ or Standard Operating Quotient will give you a general idea as to whether you are within energy consumption limits or not; The percentage uplift within each banding (within tolerance) will determine whether you are consuming less than what would be expected for someone with a similar profile like yours including age, gender, and lifestyle.

The DMSP can override the breach of any energy that is below a certain threshold with the use of an “override flag.” When this happens, even if your inner tolerance has not been reached yet and you are just on its outer edge, it will still be accepted.

If for any reason a valid reading is not received by 13:00hrs on GFD+!, the GT creates an estimated reading based on the previous days, or 7 days earlier, known as a D-7 estimate. If you have not recorded your previous consumption, the estimate is made up of AQ / 365.

Can I change gas supply classes?

In short, it is possible to change gas supply classes, but it it important to remember that if you decide to switch from Class 1 to another, then it is extremely important for the AMR device itself and not just its settings in order be changed. The only way this can happen automatically is by replacing your Shipper with one of our approved models before transferring out so DMSP will know which version they need when installing theirs on behalf of GT.

When the Registered User changes the Class of their Supply Meter Point, they are making an important decision that will affect how much power is available at this location. If you change your point to a lower class because it’s too far away from a Distribution Management System (DMS), then there won’t be enough energy for homes and businesses in your area.

On top of potentially causing brownouts or blackouts, poor management could result in fines levied by regulators as well! It’s worth considering what other options might exist before changing anything on our site-contact us if we can help with any questions about supply points near you!

Class 2

In contrast to the Class 1 statistics above, a Class 2 site will have an AQ less than 58.6Kwh, and its class is determined by the Shipper. While it holds many similarities when it comes to collecting usage data to the above class, An Automated Meter Reading device is not mandatory on Class 2 sites, and where daily reads are provided before the D+5 or the read date, the consumption will then feed allocation and Energy Balancing Processes.

There are a handful of aspects taken into account in order to ensure that the file can be submitted. These are listed below, though this list is not exclusive and others may use more, or different processes:

  • The file format must be completed correctly
  • SMP is part of a Shipper portfolio
  • The Meter Serial Number (MSN) matches
  • Energy Tolerance checks, explained above.

Changing from class 2…

When you are changing from class 2 up to 3 o, AMR will be present, but it is not required that you change the kit on a class change only event this time. An actual read will be required when changing class in order to close out the outgoing class at that time; this is validated with an AMR present in order to ensure and validate the reading back to the last site visit, and will include energy tolerance checks.

Tolerance Bands for Class 1&2 sites

Lower AW band (kWh)Upper AQ band (kWhTolerances where read will be acceptedTolerances where a Read will be Accepted if Submitted within Override Flag (Inner Tolerance)Outer Tolerance Where Read will be Rejected (Market Breaker)
110% – 20,000,000% of SOQ2,000,0001% – 7,000,000% of SOQ>= 7,000,001% of SOQ
22000% – 10,000% of SOQ10,001% – 25,000% of SOQ>= 25,001% of SOQ
2011,0000% – 4,000% of SOQ4,001% 10,000% of SOQ>= 10,001% of SOQ
5015,0000% – 2,000% of SOQ2,001% – 5,000% of SOQ>= 5,001% of SOQ
1,00110,0000% – 400% of SOQ401% – 2,000% of SOQ>= 2,001% of SOQ
5,00120,0000% – 200% of SOQ201% – 500% of SOQ>= 501% of SOQ
10,00173,2000% – 150% of SOQ151% – 400% of SOQ>= 401% of SOQ
20,001732,0000% – 300% of SOQ301% – 600% of SOQ>= 601% of SOQ
73,2012,106,0000% – 250% of SOQ251% – 550% of SOQ>= 551% of SOQ
732,0012,196,0000% 200% of SOQ201% – 500% of SOQ>= 501% of SOQ
2,196,00129,300,0000% – 150% of SOQ151% – 450% of SOQ>= 451% of SOQ
29,300,00158,600,0000% – 100% of SOQ101% – 400% of SOQ>= 401% of SOQ
58,600,001And above0% – 100% of SOQ101% – 350% of SOQ>= 351% of SOQ

One of the big differences for Class 1 and 2 sites with Invoicing is how much they offer in terms of supporting information.

The Supporting Information file accompanies your core invoices, displaying the charge information at SMP level for Class 1 & 2 sites so you can see charges per site. For those of us who want to drill down further into our monthly expenses there is a separate supporting files that displays this same data aggregated by month and year-to-date breaking out how we spend money on each individual site class from 3 through 4.

The necessary file types are as follows…

Core InvoiceInvoiceSupporting information – Level 1Supporting Information – Level 2
COMCommodityCOMCOI
CAZCapacityZCSCZI
AMSAmendmentASPAML

Class 3

The stand out difference between this class to the others is that a Class 3 site will have 2 AQs, a Rolling and a Billing AQ.

There are a handful of aspects taken into account in order to ensure that the file can be submitted, and more required for a class 3 site than the former;

  • The file format must be completed correctly
  • SMP is part of a Shipper portfolio
  • The Meter Serial Number (MSN) matches
  • Energy Tolerance checks, explained above.
  • A Meter Reading for a Class 3 Supply Meter Point where the Read Date falls within calendar month M is only valid when submitted not later than 10 days after it’s read date. This means that you need to submit your meter reading for a class 3 supply point by the 10th day of next month if it falls in this calendar month. After you are outside of the read submission window in this class, the reading can only be replaced by the Shipper who held responsibility over that site on the data of the previous Meter Read. As you cannot fit new reads in between.

For EUC01 sites only, following MOD700, the system will automatically validate the latest batch that it receives, and if a read is confirmed as validated then all other valid reads in this batch are marked ‘assured’. If any of these batches fails validation for one or more reads, we mark them both invalid (or un-validated) before moving on to next set of submitted readings.

Changing from class 3…

The NOM & CONF process, otherwise known as Nomination and Confirmation process is the primary way in which a shipper is able to change the class of a site. A Shipper may also use the SPC file in order to change the class of your site.

You are expected to give a minimum of 5 and a maximum of 30 business days notice to change the class of your site using an SPC file.

If a class 3 or 4 is being changed to class 2 or 1 then the required DMSOQ must be the equivalent of the current Billing/SMP NDM SOQ value.

You will then need to provide DMSHQ value ad this needs to be in ratio to the requested DMSOQ. This is expected to be between 1:4 and 1:24, otherwise you will not qualify.

Class 4

Sites that would previously have been NDM sites were automatically placed into Class 4 as part of the Nexus Project. Reads from Class 4 sites are sent periodically by the Shipper; either each quarter, each annual or each month.

There are a handful of aspects taken into account in order to ensure that the file can be submitted, and as we can see above, classes 3 and 4 are where we start to see some changes in these necessary steps. A Class 4 site must have:

  • The file format must be completed correctly
  • SMP is part of a Shipper portfolio
  • The Meter Serial Number (MSN) matches
  • Energy Tolerance checks, explained above.
  • They also must ensure that a meter reading is valid by checking that it is not too old. A Read for Class 4 site is only valid 25 Supply Point business days beyond the read date on Monday morning at 8:00 AM EST. Only a shipper will be able to change the meter reading outside of the submission window if you are to submit those details later.
  • Reads are less common for these types of sites, and your read will not be accepted in a number of circumstances, but primarily if the period from the last read date to the submitted read date, is:
    • For a Monthly Read Meter less than 7 Calendar days
  • For an Annual Read Meter at an LSP less than 14 Calendar days
  • For an Annual Read Meter at an SMP less than 25 Calendar days

Changing from class 4…

When you want to change the class of your site, there are two main options. The Shipper can submit a nomination and confirmation request and wait for confirmation or use an SPC file with at least 5 days notice- but no more than 30.

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