An adjustment that allocates an amount to a partial period or a change during a billing cycle, using a defined calculation method. It is the calculation used when the customer buys less than a full standard period, or changes the amount of service partway through it.
An example
Under a monthly proration rule, an add-on priced at S$12,000 per year costs S$6,000 for six complete months. A daily calculation can produce a different amount, especially across months with different lengths.
What to check
Confirm the day-count method, effective dates, rounding and treatment of credits before comparing amounts.
In practice
Record the calculation basis, start and end dates, rounding and applicable credits. Use the method in the agreement or approved pricing guidance rather than choosing whichever produces the preferred number.