What are the different expense splitting methods and when to use each?

Expense sharing in Kai has two layers: how a shared cost is divided (the split method), and whether a given expense is shared at all.

The split method (group-wide)

Set under Group settings → Financial → Expense sharing (or quickly in Essentials → Money). It decides how a shared cost is divided:

• Equal: evenly across all active members. Example: €200 fuel ÷ 4 = €50 each.
• Proportional to ownership: by each member's ownership percentage, or share count if your group uses share-based ownership. Example: A 40% / B 30% / C 30% → a €1,000 cost becomes €400 / €300 / €300.
• Don't split (owner pays): expenses stay un-split. Use this when one member absorbs all costs and bills the others by usage.

Whether an expense is shared (per expense)

Not every expense should be split: fuel you burned yourself is your cost, while a new set of sails is everyone's. That choice is made per expense, and how it works depends on whether your group uses invoicing:

• Invoicing groups: a member-paid expense defaults to reimbursing the payer (you are paid back in full and nothing is split). Turn on Split cost among members on the expense to split it instead, using the group's method above.
• Non-invoicing groups: every expense is split among members automatically; there is no per-expense opt-out. To get the "keep it on the payer" option, turn on invoicing (Essentials → Money → Invoicing).
• Paid by the group: for costs paid straight from the shared group account: no one is reimbursed, but members still owe their share to the group.

Example

You hold 2 shares; three others hold 10 each, and the group uses invoicing with Proportional to ownership:

• You buy €120 of fuel for your own trip → leave Split cost among members off → nothing is split, the group reimburses you the €120, and your trip's cost reaches you through your usage billing.
• The group replaces a €3,200 sail → turn it on → it splits by shares: your part is about €200 (2 of 32 shares) and each 10-share owner about €1,000.

Where each lives

• Split method: Group settings → Financial → Expense sharing (or Essentials → Money).
• Split vs reimburse, per expense: the Split cost among members toggle on the expense form (invoicing groups only).

Document your setup so members understand how their balances move after each expense.