LLFC

The LLFC is arguably the most important code on your MPAN for billing purposes. This three-character code (which can include letters and numbers) acts as the bridge between your meter and the tariff rates you pay. Every LLFC maps to a specific tariff category, which determines your unit rates, standing charges, and capacity charges.

Different LLFCs exist because electricity loses some energy as it travels through the network - supplies connected at higher voltages (like factories with their own substations) lose less energy than domestic supplies at standard voltage. The LLFC captures this difference along with other characteristics like your metering type.

Key facts about LLFCs:

• Alphanumeric since 2016: Following BSC Change Proposal CP1434 (30 June 2016), LLFCs can contain letters A-Z (excluding I and O to avoid confusion with 1 and 0)
• Examples: 001, N01, P80, LST, HST
• Market segments: Domestic, Non-Domestic, Generation (export), Unmetered (street lighting)
• Voltage levels: LV (Low Voltage), LV Sub, HV (High Voltage), EHV (Extra High Voltage)

Billing errors often stem from an incorrect LLFC being applied. If your supply has been upgraded, moved, or changed, the LLFC might not have been updated correctly. This is one of the first things to check if you suspect you're being overcharged.

How LLFC-to-Tariff Mapping Works

Each DNO publishes an LLFC schedule (typically in Annex 3 of their charging statement) that maps every LLFC to a tariff category. Multiple LLFCs can map to the same tariff because they represent different physical configurations that have the same charging treatment.

Why New LLFCs Appear Mid-Year

DNOs occasionally publish revised charging statements (v1.0 → v1.1) during a charging year:

• What changes: New LLFC codes for new meter configurations or IDNO networks
• What stays the same: All tariff rates remain unchanged

For bill validation, always use the latest version of the charging statement.