Why There Are 32 Tariff Categories
Tariff StructureThe CDCM standardises DUoS pricing into 32 categories that balance simplicity with cost-reflectivity across all customer types.
Before the Common Distribution Charging Methodology (CDCM) was introduced, each DNO had its own tariff structure with different names, bands, and categories. This made it nearly impossible to compare charges across regions.
The 32 categories cover:
| Dimension | Options |
|---|---|
| Market segment | Domestic, Non-Domestic, Unmetered |
| Size band | Small, Medium, Large |
| Metering | Aggregated, Half-Hourly |
| Voltage | LV, LV Sub, HV |
| Time configuration | Unrestricted, Two Rate, Three Rate |
Why standardisation matters:
- Comparison: You can now compare equivalent tariffs across DNOs
- Billing validation: Systems can validate charges against published rates
- Portability: Switching supplier doesn't affect your tariff category
The LLFC code on your MPAN determines which of the 32 categories applies. Each DNO publishes a mapping table showing which LLFCs map to which tariff categories.
Note: EDCM (EHV) customers are NOT covered by these 32 categories - they have individually-calculated site-specific tariffs.
Related terms
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