Concept
What the service period on a water bill means
A customer holds up their January bill and asks what it's for. The answer is printed on it: Service Period: 10/01/2026 – 12/31/2026. Water is billed in arrears, for service already received, so the January 1 bill covers October, November and December. The service period is how BasicBMS keeps those dates straight, so that no day is billed twice, none is skipped, and a customer who leaves mid-quarter pays for exactly the days they had.
Terms used here
- Bill date: the day the recurring schedule runs, such as January 1.
- Cycle: the stretch between one bill date and the next. A quarter from October 1 to January 1 is 92 days.
- Service Start: the date on the service point when service began there.
- Fixed charge: a charge that bills once per bill, such as the base service charge. Usage is billed from reads instead.
How it works in BasicBMS
Every bill cut for a service point works out its own period from three rules:
It ends the day before the bill date. The January 1 bill ends on December 31.
It starts the day after this point's last billed period. If the point has never been billed, it starts on the previous bill date.
It never starts before the point's Service Start. A connection that came on in November isn't billed for October.
Because each period starts where the last one ended, the periods chain end to end. A quarter that was partly billed already, by a final bill for instance, only bills the days that are left.
The period prints in the bill header as Service Period:, next to Service Point #:. Only bills cut for a service point carry it. An ordinary invoice for a part or an hour of labor doesn't show the line at all.
When the period is shorter than the cycle, the fixed charges are prorated by days: the charge, times the days in the period, divided by the days in the cycle. The line says so, for example Quarterly Flat Rate (46 of 92 days). (screenshot: bill header with Service Period and a prorated line)
On a $150 quarterly rate with a 92-day quarter starting October 1:
| Situation | Period | Days | Fixed charge |
|---|---|---|---|
| Full quarter, bill dated January 1 | 10/01 – 12/31 | 92 of 92 | 150.00 |
| Owner moves out November 15 (final bill) | 10/01 – 11/15 | 46 of 92 | 75.00 |
| New owner's first bill, January 1 | 11/16 – 12/31 | 46 of 92 | 75.00 |
| Owner moves out December 1 (final bill) | 10/01 – 12/01 | 62 of 92 | 101.09 |
The two halves of the November sale add up to the full $150. Nothing is double-billed and nothing is lost, and nobody did the arithmetic on a calculator.
Usage isn't prorated. It's billed from the reads themselves, so the period decides which reads belong on the bill (those for periods ending on or before its last day), not how much to charge for them.
What posts behind it
The period is a label and a proration rule. It posts nothing by itself. The bill posts as it always does, at its prorated amount. The November 15 final bill above:
| Account | Debit | Credit | |
|---|---|---|---|
| DR | Accounts Receivable | 75.00 | — |
| CR | The rate item's GL Sales account (or GL Defaults Inventory Sales) | — | 75.00 |
| Balanced | 75.00 | 75.00 |
When it won’t let you
This point is already billed through 11/15/2026; there is nothing left to bill to 11/15/2026. A final bill was asked for dates the point has already been billed for. The chain rule at work: the next period starts on November 16, so there is nothing left in the range you picked.
What this doesn't do
There are no refunds or credits for a period billed in advance, because nothing is billed in advance: every bill is for days already past. Usage is never prorated, only fixed charges. And invoices that aren't cut for a service point have no service period.
Related
Questions about how this fits your system? Call (509) 955-0770.
Business software as unique as your business.
Water Utility→
Property Management→
General Business→
Construction soon
Don’t see yours? Build a vertical →
