How to Split a Water Bill Between Tenants
· 7 min read
One water meter, several tenants, and a bill that arrives quarterly for an amount nobody can explain. This is the most common utility problem in small multifamily property, and there are four defensible ways to solve it.
Start by deciding what drives the usage
Water is consumed by people, not by rooms. Showers, laundry, dishes, and toilets all scale with how many humans live in a unit, which is why occupant-based allocation is the most widely accepted method for water and sewer — and why several states specifically name it in statute.
Square footage is the conventional choice for heating and cooling, where the driver is volume of space. Using square footage for water is defensible in a building where units differ a lot in size and occupancy is stable, but it is harder to justify to a tenant living alone in the largest unit.
The four methods
| Method | The arithmetic | Where it holds up |
|---|---|---|
| Equal split | Bill ÷ number of units | Identical units with similar occupancy |
| By occupants | Bill × (unit occupants ÷ total occupants) | The default for water and sewer |
| By square footage | Bill × (unit sq ft ÷ total sq ft) | Units of very different sizes |
| Custom percentages | Fixed shares agreed in the lease | Mixed-use, or a unit with a known heavy draw |
A worked example
A $151.13 water and sewer bill across three units. Unit A has one occupant, Unit B has two, Unit C has three — six occupants in total.
| Unit | Occupants | Share | Amount |
|---|---|---|---|
| A | 1 | 1 of 6 | $25.19 |
| B | 2 | 2 of 6 | $50.38 |
| C | 3 | 3 of 6 | $75.56 |
| Total | 6 | $151.13 |
Note that the shares add to the bill exactly. Rounding is where landlords quietly overcharge: if you round each share up to the nearest cent independently, you can collect more than the utility charged you, which is prohibited in essentially every state that regulates this. Allocate the remainder cent to one unit instead of rounding each one up.
If one unit has its own meter
What you owe the tenant in writing
Whatever method you choose, a tenant bill that survives a dispute shows:
- The utility company's total for the period, and the exact service dates it covers
- The allocation method, stated plainly
- The inputs used for this unit — occupants, square feet, or the meter reading
- The resulting share, and any admin fee shown as a separate line
- How and when to pay, and who to contact about an error
The service dates matter more than landlords expect. "July" is ambiguous; "June 28 to July 29" is not. When a tenant says they have already been charged for July, dated periods are what let you show otherwise.
Vacant units and your own unit
A vacant unit still consumes water, and its share is the owner's cost. Several jurisdictions say so explicitly — Jersey City, for instance, prohibits charging tenants for vacant units. The same goes for a unit you occupy yourself. Pushing those shares onto the remaining tenants means billing them more than their proportional cost, which is the thing every statute is written to prevent.
State rules to check first
Texas is the strictest common case: allocated water and wastewater billing requires registration with the PUC, limits which methods you may use, and requires a common-area deduction.
Minnesota takes a different approach, prescribing the method by utility type rather than registration.
Check the rules for your state →
Let the arithmetic happen by itself
SplitDue splits the bill, generates a PDF for each tenant, and records which periods you have already billed. 14-day free trial.
This article is general information, not legal advice. Utility billing rules vary by state and sometimes by city. Confirm your local requirements before billing tenants.