Explorer

Proration

billing and meteringv0.4.0Updated 2026-07-10

Canonical Definition

Proration is the adjustment of utility charges to reflect a billing period that differs from the standard length, or a mid-period change such as starting service, ending service, or switching rates. Fixed monthly charges are typically prorated by the ratio of actual service days to standard days, and tiered usage allowances may be prorated similarly. Proration ensures customers pay only for the portion of the period during which the charge applied; methods are defined in utility tariffs.

Explanations

Proration means adjusting charges to match a partial or unusual billing period. For example, if you start service in the middle of a billing cycle, fixed monthly fees are split so you pay only for the days you had service. Utilities also prorate when a billing period is longer or shorter than usual or when your rate changes mid-period. The goal is that you pay only for what applied during your actual service days.

Analogy Bank

general

Proration is like splitting a streaming subscription mid-month — you pay only for the days you actually had it.

general

It's like a gym charging you from your join date instead of for the whole month before you were a member.

homeowners

When you move in mid-cycle, proration works like the tax settlement at a home closing — costs split by who held the home on which days.

Do Not Say

  • Do not calculate a customer's prorated charges yourself; methods are defined in each utility's tariff.
  • Do not assume tiered usage allowances are prorated the same way everywhere; practices vary by utility.