Billing Period

The billing period defines the start and end dates covered by your invoice. While this seems simple, it's crucial for accurate bill validation - fixed charges and capacity charges are calculated per day, so the number of days directly affects the amount.

Why billing periods matter:

• Fixed charges = Rate x Days in period
• Capacity charges = Rate x kVA x Days in period
• Cross-year billing - Periods spanning rate changes need pro-rata calculation

Common billing period issues:

• Day count errors - Invoice calculates 30 days but period covers 31
• Rate change handling - April rate changes not applied correctly mid-period
• Overlap/gaps - Consecutive invoices that double-count or miss days

How EnergyCode handles billing periods: When you enter a billing period, EnergyCode:

1. Counts the correct number of days (inclusive vs exclusive dates)
2. Identifies if the period spans a rate change (typically 1 April)
3. Applies pro-rata calculation if rates changed mid-period
4. Flags any discrepancies with your invoice

Cross-year example: A billing period of 15 March to 14 April spans the 1 April rate change. EnergyCode calculates:

• 17 days at 2024-25 rates
• 14 days at 2025-26 rates
• Weighted average for comparison