Bill every flat for its own electricity.

The reading is all you type.

The usage is the difference from that meter’s last reading. Rentio holds the previous value for each meter separately, so two sub-meters on one flat never compute each other’s usage, and replacing a meter does not corrupt the history.

Rates — including the one flat that pays differently.

Set a rate for the building and override it for any flat. Rates carry the date they took effect, so a mid-year revision applies from that day forward and older readings keep the rate they were actually billed at.

Type in whichever figure you actually have.

Rentio works out whatever else it can and remembers which figure you gave it, so the arithmetic can always be explained later.

• The meter reading, as you read it off the dial.
• The units used, when you know the usage but not the meter position.
• The amount, straight off the provider’s bill — which is what you need the moment slabs, fixed charges and taxes are involved.

Writing it down is not billing it.

A reading charges nobody on its own. You see what the month comes to, then add the charge as a separate step from a form you can edit first. That is the last point at which the provider’s real number can replace the estimate — before a tenant sees it, rather than as an apology afterwards.

Late and out-of-order entries fix themselves.

Type in a reading you took last month and forgot to record, and every later reading on that meter is worked out again — with any charge already added corrected, and a note explaining why. If the correction would push a later month below zero or reach into a year you have already closed, the whole thing is refused rather than half-applied.

Water and gas too.

Water charges carry the month they bill, so the register shows water paid up to which month and warns you about a gap or a duplicate. Gas works the same way.

Shared meters, split fairly.

For a common-area meter or a building bill — lift, cleaning, security — set how it divides between the flats and post one month at a time. The shares always add back exactly to the total, to the paisa. An empty flat’s share is carried by you, never pushed onto the neighbours.