The Fairness Engine

Proportional splits

When everyone doesn't stay the full month, we weight each person's share by their active days—so nobody subsidizes someone else's travel.

Guest fees & house rules

Long-term guests? One-off costs? Your house can decide what counts and who pays—so the rules stay transparent.

Stock buy-backs

When someone moves out—or the group buys shared supplies—we keep transfers explicit so nobody's left holding the bag.

Example: one roommate buys a shared router. Later, when someone leaves, HabiMate can record a clean "buy-back" so ownership (and the money) stays fair.

Calculations, cents & rounding

Money is stored and split in whole cents so shares add up to the total you enter. When a total does not divide evenly (for example €10.00 split three ways), the extra cent is assigned using a fixed rule: remainder cents go to participants in a stable order (the same order your house uses in the app for that split). That way nothing “vanishes,” and the math is consistent and auditable.

Bill splits and stock buy-backs both follow this cent-safe approach. Buy-backs are recorded as separate transfers from your shared expense totals so reimbursements stay clear.

Important. HabiMate helps your household track and agree on numbers. It does not decide legal disputes, enforce payments, or replace professional advice. For tax, tenancy, deposits, or court matters, keep your own records and consult a qualified professional. See also our Privacy & Trust page for how we describe limitations on liability in plain language.