Business Energy Glossary
What is a Data Collector (DC) and Data Aggregator (DA)?
The Data Collector, or DC, and the Data Aggregator, or DA, are the UK industry parties responsible for the data flow on half-hourly metered electricity supplies. The DC retrieves consumption data from each HH meter and processes it into a standardised format. The DA aggregates the data and submits it to the central settlement system run by Elexon. Both roles are required on every half-hourly supply today. Under market-wide half-hourly settlement, they are being replaced by new data service roles, with migration due to complete in 2027. They typically work alongside the Meter Operator (MOP) as the three-party metering supply chain.
DC and DA are invisible to most customers but their work underpins every half-hourly bill. Understanding the roles helps when investigating data issues, planning supplier-bundled versus customer-appointed metering arrangements, or evaluating broker services for larger sites.
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The DC and DA roles
Data collectors retrieve and validate half-hourly electricity readings, and data aggregators combine them for the settlement system, though market-wide half-hourly settlement is replacing both roles. Their fees are usually built into half-hourly supply contracts, and gaps in their data lead to estimated charges.
For the full explanation, see Meter Operator Contracts Explained.
The two roles are distinct:
- Data Collector (DC). Retrieves the half-hourly consumption data from the meter (via communications hub or AMR equipment), validates it, and produces standardised data files.
- Data Aggregator (DA). Aggregates DC-produced data across multiple meters in the supplier portfolio and submits the aggregated data to Elexon for the daily settlement process.
Together with the Meter Operator (MOP), the DC and DA form the metering supply chain.
How they work together
The daily process:
- The HH meter records consumption in 30-minute periods, generating 48 readings per day.
- The MOP keeps the meter operational; the DC retrieves the data via the meter communications equipment.
- The DC validates the data (correct format, no gaps, no clearly erroneous readings) and forwards to the DA.
- The DA aggregates data across the supplier portfolio and submits to Elexon at scheduled times.
- Elexon uses the aggregated data for industry-wide settlement, matching total consumption to total generation.
- The supplier uses the DC-produced data for individual customer billing.
How DCs and DAs are appointed
Two appointment models:
- Supplier-appointed (most common). The energy supplier holds framework contracts with DCs and DAs and appoints them as part of the supply contract. The cost is bundled into the unit rate or standing charge.
- Customer-appointed. Larger half-hourly customers contract directly with a DC and DA separately from the supplier. The fees are invoiced separately. The customer can choose the providers based on service quality and price.
Customer-appointed DC and DA contracts are common above 1 MW of total HH consumption, where the savings against supplier-bundled rates justify the administrative effort.
DC and DA fees
Typical annual fees per HH meter point:
| Role | Typical annual fee |
|---|---|
| Data Collector (DC) | £40 to £100 |
| Data Aggregator (DA) | £30 to £80 |
| Combined DC/DA bundle | £70 to £180 |
Many providers offer DC and DA as a bundled service since the two roles work closely together. Larger customers can negotiate volume discounts.
Customer-appointed vs supplier-bundled
Comparison:
| Factor | Supplier-bundled | Customer-appointed |
|---|---|---|
| Cost | Higher; supplier margin added | Lower; direct contract pricing |
| Service choice | Limited to supplier-appointed providers | Full choice of any accredited provider |
| Administrative complexity | One bill from the supplier | Multiple bills: energy + MOP + DC + DA |
| Service coordination | Supplier handles issues | Customer manages service relationships |
| Switching supplier | Provider may change at supplier switch | DC/DA stay regardless of supplier change |
Changing DC or DA
For customer-appointed contracts, switching DC or DA is administrative:
- Sign new contract with the preferred provider.
- Notify the existing provider of the change date.
- The new provider takes over data retrieval and processing on the transition date.
- Notify the supplier of the change so billing systems are updated.
The physical meter does not change. The data flow continues uninterrupted. Most customers do not notice the change beyond seeing different invoices.
a Data Collector (DC) and Data Aggregator (DA) FAQs
What is a Data Collector (DC)?
The UK industry party responsible for retrieving half-hourly consumption data from electricity meters and processing it into standardised format for use by the supplier and the central settlement system.
What is a Data Aggregator (DA)?
The UK industry party responsible for aggregating DC-produced data across multiple meters and submitting the aggregated data to Elexon for the daily settlement process.
What is the difference between DC, DA, and MOP?
The MOP installs and maintains the physical meter. The DC retrieves the data from the meter. The DA aggregates the data for industry settlement. All three roles are required on every UK HH metered supply.
How much do DC and DA fees cost?
Typical annual fees: £40 to £100 for DC, £30 to £80 for DA, or £70 to £180 for a combined DC/DA bundle. Larger customers can negotiate volume discounts.
Should I appoint my own DC and DA?
For HH portfolios above 1 MW total consumption, customer-appointed DC and DA typically save 20 to 40 per cent against supplier-bundled rates. For smaller portfolios, supplier-bundled is usually simpler.
Can I switch DC or DA?
Yes, on customer-appointed contracts. Sign with the new provider, notify the existing provider, and the change is administrative. The physical meter does not change.
Are DC and DA always provided together?
Often, because the roles work closely together. Many providers offer DC and DA as a bundled service. Some larger customers split the roles between providers for specific reasons.
Do DC and DA fees appear on my bill?
On a supplier-bundled arrangement, no; the fees are included in the unit rate or standing charge. On a customer-appointed arrangement, the DC and DA invoice separately from the energy supplier.