September Shared Costs

Why September stands on its own

Both ledgers cover the whole month, and the household has shared one rent bill since August:

Rent borne, by month (net)
Party	Jul	Aug	Sep
Ben	−8,861.92	−3,000.00	−3,149.26
Cheryl	−1,000.00	−1,500.00	−1,500.00

July is Ben's move and Cheryl's last month at her previous place. From August Cheryl pays an agreed $1,500 a month toward the $4,500 rent, and Ben carries the rest. September's Rent line also holds a $67.55 Wei & Hung charge and an $81.71 U-Haul charge, both paid by Ben.

The docket

Rent is settled at the agreed $1,500; every other line splits equally. Amounts are net: reimbursements are already booked against the bills they offset.

period 2026-09-01 → 2026-09-30 parties Ben, Cheryl basis equal (50 / 50) · rent: Cheryl fixed $1,500

№	Item	Ben paid	Cheryl paid	Combined	Ben owes	Ben variance
1	Rent	−3,149.26	−1,500.00	−4,649.26	−3,149.26	0.00
2	Amazon purchases (household)	−393.03	−175.41	−568.44	−284.22	−108.81
3	Groceries	−257.64	−324.78	−582.42	−291.21	+33.57
4	PG&E	−159.52	—	−159.52	−79.76	−79.76
5	Internet	−70.00	—	−70.00	−35.00	−35.00
6	Renters insurance	−41.13	—	−41.13	−20.57	−20.56
	Paid	−4,070.58	−2,000.19	−6,070.77
	Obligation	−3,860.02	−2,210.76	−6,070.78
	Variance	−210.56	+210.57

Cheryl to Ben $210.56 equal split · rent fixed at $1,500
1–30 Sep 2026 · six items

Outside the docket

Cheryl's $34.00 Zelle on 9 September was her half of the July water bill (the $67.55 Wei & Hung charge inside Rent). It is filed as a reimbursement, so it is not credited above; crediting it brings the position to $176.56.

The utilities are being settled separately: the 8 October email asked Cheryl for $208.44 — September PG&E, internet and renters insurance, plus October's water. Once that is paid, what remains from this docket is the Amazon and groceries balance: $75.24.

The basis changes the answer

With rent pinned by agreement, the basis only moves the smaller lines. Weighting by September income (Ben $6,474.01, Cheryl $4,733.64) shifts more of them onto Ben.

Equal · rent fixed

$210.56

Cheryl to Ben. Her obligation is $1,500 of rent plus half of everything else: $2,210.76.

By income · 57.8 / 42.2 · rent fixed

$100.20

Cheryl to Ben. Ben's larger September income, mostly Renee's support, raises his share of the smaller lines.

Equal · rent split 50 / 50

$1,035.19

Not the arrangement — it halves the full $4,649.26 of rent, ignoring the agreed $1,500.

The third figure is shown so it can be discounted: splitting rent evenly contradicts the agreement the household actually runs on.

What the lines say

Rent settles exactly

Cheryl's $1,500 matches the agreement, so the largest line contributes nothing to the variance.

Groceries tilt to Cheryl

$324.78 against $257.64, so this line reduces what she owes by $33.57.

Amazon counts household orders only

Both cards buy on Cheryl's Amazon account. Read from the invoices, Ben's $655.98 was $393.03 household (groceries, protein bars, paper towels, delivery tips) and $262.95 his own (protein shakes, Pedialyte, kids' medicine and socks, creatine, melatonin, a van hitch, a charger). Cheryl's $247.00 was $175.41 household and $71.59 her own (shoes, vitamins, Lactaid, floss). Only the household part is shared, adding $108.81.

Ben paid every utility

PG&E ($159.52), Internet ($70.00) and renters insurance ($41.13) all came from Ben, adding $135.32 together. Cheryl's October Xfinity Zelle falls outside September.

Renters insurance is now just the renters part

Only $41.13 of the $187.13 USAA bill is household cost; the car-insurance remainder is Ben's.