MIC / Agreed Capacity

Maximum Import Capacity (MIC) is the maximum power (in kVA) that your electricity connection is designed to supply at any moment. It's agreed between you and the DNO when the connection is established and recorded in your connection agreement.

Why MIC matters: MIC directly affects two charges on your bill:

• DUoS Capacity Charge - For Site Specific tariffs: MIC × p/kVA/day × days
• TNUoS TDR Band - Since April 2023, your MIC determines which fixed band you fall into

Example calculation:

• MIC: 200 kVA
• Capacity Rate: 1.50 p/kVA/day
• 30-day month
• Charge: 200 × 1.50 × 30 = 9,000 pence = £90.00

TNUoS TDR Bands (determined by MIC):

The MIC data access problem: A common industry challenge is obtaining accurate MIC data before receiving the first DUoS bill. Unlike meter readings that flow through standard industry data channels, MIC is connection data stored by DNOs but not routinely shared via systems like ElectraLink/ECOES.

Options for obtaining MIC data:

Why ElectraLink data is often incomplete: MIC isn't a mandatory field in standard industry data flows (DTS). The switching and settlement systems were built around meter readings, not connection agreements. Many historical connections pre-date digital systems and were never properly captured.

Changing your MIC: If your requirements change, you can request a capacity increase or decrease from your DNO. This may involve:

• Application fee
• Possible network reinforcement costs (if increasing)
• New connection agreement
• Updated capacity charges from the effective date

Bill validation tip: If the capacity charged on your DUoS invoice doesn't match your connection agreement, this is a billing error. Also check that your TNUoS TDR band is consistent with your MIC - wrong band = wrong charges.