The list on the phone of whoever didn't go
Written in one person's notes app, or in a message from three days ago you have to scroll up to find.
The moment to know the coffee has run out is when you pour the last cup, not when you're standing in the supermarket aisle trying to remember what was missing.
What happens without it
Written in one person's notes app, or in a message from three days ago you have to scroll up to find.
Two people go shopping the same day without knowing and both come back with milk. It gets thrown away, and it's been paid for twice.
Someone fronts £84 and has to remember to ask for it back, or decide it doesn't matter. Neither of those is good in the long run.
How it gets sorted
What one person adds appears for another without reloading anything. It can be added from the kitchen the moment something runs out, which is when it actually gets written down.
The shop is closed, the items go into the pantry with their quantities, and the receipt total becomes an expense split between whoever it's for. In one step and one operation.
If you keep the pantry, anything that drops below the minimum you set reappears without anybody remembering to add it.
From the kitchen to the accounts, with nothing in between
Setting up a home takes under a minute, and you decide later whether you need anything more.