RUBS billing: prorating move-ins, move-outs and vacant days

RUBS billing is wrong the moment it ignores the calendar. A tenant who moved in on the 12th should not pay for the 1st to the 11th, and an empty unit's share has to land on someone. The fix is to weight each lease by its basis (occupants, square feet or 1) times the days it covers in the service period, then decide whether vacant days stay with the owner. The calculator above does this on your rent roll, and this guide shows how.

How do you prorate RUBS billing for a move-in?

Count the days the lease covers inside the service period, counting both the first and the last day, and weight the unit by that. A tenant moving in on the 12th of a 30-day period covers days 12 to 30, which is 19 days. Their share is their basis times 19, over the total of everyone's basis times days.

Take a $300.00 water bill for three equal-weight units over a 30-day period. Units 1 and 2 are occupied all month, so they weigh 30 each. Unit 3's old tenant left after the 11th and its new tenant moved in on the 12th, so they weigh 11 and 19. The total is 90, so each weight is worth $3.3333. Units 1 and 2 pay $100.00, the new tenant pays $63.33 and the old tenant pays $36.67, which add up to $300.00. Neither tenant pays for days that were not theirs.

How do you prorate for a move-out?

The same way, from the other end. The tenant's days run from the period's first day to their last day on the lease. If unit 3's tenant moves out after day 20, they weigh 20, and the days from the 21st on are vacant unless a new lease starts.

When one unit has a move-out and a move-in in the same period, each lease is its own party with its own days, so each tenant is charged only for their own. That is why leases, not units, are the thing to weight. Utility Billback keeps leases as separate rows for this reason, so a re-uploaded rent roll updates the units and replaces their leases.

Who pays for vacant days?

The vacant days belong to the owner, or the occupied units share them. It is a choice, and it should match the lease. Using the same example with unit 3 empty for the last 10 days of a 30-day period, equal weights and a $300.00 bill:

• Vacant days stay with the owner. Weights are 30, 30 and 20, plus 10 vacant, which total 90. Each weight is worth $3.3333. Units 1 and 2 pay $100.00, unit 3's tenant pays $66.67 and the owner keeps $33.33.
• Vacant days are shared. Only occupied unit-days count: 30, 30 and 20, total 80. Each is worth $3.75, so units 1 and 2 pay $112.50 and unit 3's tenant pays $75.00. The owner keeps nothing.

The second way charges the other tenants for a vacancy they did not cause. Many managers use the first, and Utility Billback defaults to it. Whichever you choose, check it against the lease and local law, and apply it the same way every month.

How do you keep the cents exact?

Work in whole cents, give each lease the whole cents of its share, and hand the leftover cents one at a time to the shares with the largest fractions. In the vacant-days-owner example, $300.00 is 30,000 cents. The shares are 10,000, 10,000, 6,666.67 and 3,333.33, so the whole cents are 10,000, 10,000, 6,666 and 3,333 for a total of 29,999, and the one leftover cent goes to the largest fraction, 6,666.67, giving $66.67. The charges and the owner's share then equal the bill. Rounding each share on its own can leave the total a cent off, and a tenant or an auditor will notice that sooner or later.

What about a cap on what one unit can be charged?

Some properties limit a tenant's charge per bill. The way to apply a cap is after the split: compute each unit's share, charge the lesser of the share and the cap, and treat the excess as the owner's. That keeps one unit from carrying an outlier, such as a leak, without changing the other units' shares. Utility Billback lets you set a cap per property and utility. Whether a cap is required, and how it should be disclosed, depends on your lease and local law.

What goes wrong most often in RUBS billing?

• Whole-month billing. Charging the current tenant the full period at move-in or move-out.
• Stale rent rolls. Lease dates and occupant counts that were not updated after a move.
• Vacant days spread silently. Dropping a vacant unit from the split without a decision on who pays.
• Missing service dates. Without the period's first and last day you cannot prorate. Utility Billback asks for them and will not allocate a shared bill without them.
• Bills still in your name. A unit's own bill for a tenant who never moved the account is not a shared bill: charge it to the tenant for their days and list it. See utility billback.

How do you check a prorated split?

Add up the shares and the owner's share and compare with the bill: they must match to the cent. Then recompute one lease by hand: basis times days, over the total weight, times the bill. The ratio utility billing system guide has a four-unit example to compare against, and the sample month shows the move-out and move-in in one gas bill on a 12-unit building.

Frequently asked questions

Do I count the move-in day and the move-out day?

Utility Billback counts both the first and the last day a lease covers. Whatever you choose, count them the same way every month and make sure it matches your lease.

What if the service period spans two months?

Prorate by the days within the bill's own service period, not the calendar month. The charge then belongs to the month the bill was paid or the period you choose, and that choice is a bookkeeping policy, not a rate.

Should vacant days go to the owner or to the tenants?

That is a lease and local-law question. Keeping vacant days with the owner avoids charging tenants for a vacancy they did not cause, and it is the default in Utility Billback and the RUBS calculator, which you can switch to shared days.