Repeating expenses and periods

Most nests never need to think about this. You add expenses, the balance runs, and when everyone has paid up the period closes on its own.

Because your nest grew.

You had "Once per period" turned on for a repeating expense. The nest setting that offers it, Allow repeating expenses to open new periods, is on by default for nests of two people, and off by default once a nest reaches three or more, because it stops working well at that size. When your nest passed two members, counting people added by name, Eider switched off Once per period on your repeating expense, and the nest setting is now off.

What changes from here: that repeating expense now lands in your nest's current period like every other expense, instead of opening a new period when it comes due a second time.

If you still want it, you can turn it back on. Choose the ring at the top left of the home screen to open the nest menu, choose Nest settings, then under Periods turn on Allow repeating expenses to open new periods. In a nest of three or more, Eider asks you to confirm first. The Once per period switch comes back on your repeating expenses, and you can turn it on again. Nest settings covers the rest of that screen. Read the next two sections first, because the reason it was turned off still applies.

Some expenses are large and land on a schedule. A mortgage, rent, a car payment. If one of those comes due twice inside the same period, the balance reads as though you owe twice what you really do for that month, and the period gets harder to settle rather than easier.

Turning this setting on adds a Once per period switch to each repeating expense on a monthly or longer schedule. When that switch is on and the expense comes due in a period where it has already been added once, Eider opens a new period and puts it there instead. Each payment gets its own stretch of time, so the numbers match the month.

The earlier period stays open, marked Unpaid, with its own balance. When this happens, Eider sends a notification titled A new period started. You can turn those off in the account menu, under Notifications, with New periods.

If the person who set up a repeating expense already has the bill's bank charge in the nest when the bill comes due, Eider doesn't add the repeating expense that time, so no new period opens. Eider does this only when it's sure the charge is the bill and the amounts are the same, as Your charges explains.

A period closes only when everyone is square with everyone else at the same moment. That is a much bigger ask than it sounds, because it is not about people, it is about pairs.

With two people there is one pair, so a period closes the moment you two square up. With six people there are fifteen pairs, and they all have to be square at the same time. In practice that almost never happens in a nest that keeps running. Somebody always owes somebody something.

So in a nest of three or more, a period tends to stay open indefinitely. That is fine on its own: the balance just keeps running, which is what a shared household usually wants anyway.

It stops being fine when something is opening new periods automatically. Each new period starts its own balance, the old one rarely reaches zero or closes, and they accumulate. Worse, the totals stop meaning what they look like: you can owe someone in one period and be owed by the same person in another, and because each period is anchored on its own, those two amounts do not cancel. The nest ends up displaying a much larger outstanding figure than anyone actually owes.

That is why the setting is on by default for nests of two, and off by default for nests of three or more.

When a third person joins a nest that had this on, or is added to it by name, the setting turns itself off and any repeating expenses with Once per period on stop opening new periods. Once someone in the nest has switched the setting on themselves, it stays on as the nest grows.

Whoever adds or invites that third person sees a note first, listing the repeating expenses it will change. Whoever set up each of those repeating expenses gets a notification so nothing changes behind their back, and they can turn the setting back on if the nest still wants it. You can turn that notification off in the account menu, under Notifications, with Periods turned off.