Method
Does a couple count as one share or two?
It is not the couple that decides, it is what gets consumed. Two people each eating their own dish count as two shares, couple or not; two people sharing a double room in a rental each occupy a place, so two accommodation shares. The question only genuinely arises for what is physically shared, such as a single dish or one bed within a limited capacity.
The criterion is consumption, not status
A couple is not a unit of measure. Two people each ordering their own dish consume two dishes, whether they live together or not: they count as two shares. The question only genuinely arises for what is physically shared, and that happens less often than people think.
The double room case
This is where intuition most often goes wrong. Two people in a double room occupy not one place but two, since the rental was booked on capacity. Counting them as one share would make the others pay for their second place. That said, if the double room is markedly smaller than two singles, an adjustment downwards is defensible, on the basis of floor area.
The shared dish, the only real case
When two people take one dish between them, they consume one portion and count as one share on that line, not on the whole bill. That is the nuance usually missed: the sharing applies to one specific expense, not to the entire meal. They remain two shares on drinks taken separately and on the cover charge.
Two lines beat one double share
Even when the result is identical, enter the two people separately rather than one line with two shares. The day one of them leaves early, does not drink or skips the activity, a single line has to be undone and recomputed, whereas two lines adjust independently. It is also what stops a couple who split up from taking the group's accounts down with them.
Key points
- In an expense split, the number of shares for a couple depends on what is consumed, not on the couple's status.
- Two people sharing a double room occupy two places of the booked capacity and therefore count as two accommodation shares.
- A dish shared by two people counts as one share on that expense line only, not on the whole bill.
- Entering two people separately rather than one double-share line allows their attendance and consumption to be adjusted independently.
- A double room markedly smaller than two singles justifies a downward adjustment based on floor area, not on the number of occupants.
Frequently asked questions
Does a couple in a flatshare pay one or two rent shares?
Two, unless their room is smaller than two individual rooms combined. The criterion is floor area occupied, not the number of couples.
What if they genuinely share everything during the trip?
They occupy two places and eat twice. How they share between themselves is their business, it does not reduce what the group paid.
Should their balances be merged?
It is convenient when settling up, and has no effect on the calculation. Merge at the end, not when entering expenses.