RoomProrateReading the billing period on a utility bill
Updated 2026-10-20
Splitting a bill by days only works if everyone counts the same days. Two numbers on the bill matter most: the dates the charges cover and the charges for those dates.
Find the dates the charges cover
Most bills print a period such as "1 April to 30 April" or "Service from 03/02 to 04/01". Utilities describe it in their own words; Octopus Energy, a UK supplier, calls the billing period "the time between your previous bill and your new one". Other companies and countries word it differently, so read your own bill rather than assuming.
RoomProrate asks for the first billed day and the last billed day, and counts both. April 1 to April 30 is 30 days.
When the end date is also the next start date
Some bills run between meter readings: "Reading 1 April, reading 1 May", and the next bill starts on 1 May. If you enter 1 May as the last day, that day is counted on both bills. Enter the day before, 30 April, so each day belongs to exactly one bill. If you are not sure how your supplier counts, the number of days is often printed next to the period; your entry should give the same number.
Use this period's charges, not the balance
A bill can show an opening balance, this period's charges, payments made, and a new balance. Octopus describes the charges as "the cost of energy you've used during this billing period". The balance is different: it can include an unpaid earlier bill, a credit from overpaying, or a direct debit amount set to smooth costs over the year.
Enter only the charges for the dates you typed. Settle old balances and who already paid what separately; RoomProrate does not offset payments.
Taxes and discounts
If tax is added to the whole bill, include it in the amounts you enter so the shares add up to what is actually paid. A one-off discount or credit that belongs to everyone can be subtracted from usage before you enter it. Credits that belong to one person are better settled outside the split.
Bills longer than a month
Water and some internet plans bill every two or three months. One bill in RoomProrate can cover up to 366 days, so enter the whole period as one bill rather than guessing monthly amounts.
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