When one of you loses a job
Change the split, name a date to look at it again, and leave everything else alone for a fortnight. A household whose costs were divided on two incomes cannot go on dividing them the same way when there is one, and the households that manage this best make one deliberate change quickly rather than a dozen anxious ones over a month.
Move to proportional, temporarily and out loud
The usual change is from an even split to one based on what each person currently has coming in, with an explicit note that it is for now. Both halves of that matter. Without the change, one person is paying a share they no longer have; without the words “for now”, it feels like a new permanent arrangement arrived on the worst week of somebody's year.
Cut the recurring, not the discretionary
The instinct is to stop spending on small things, which is visible, effortful and worth very little. The subscriptions list is where the actual money is, it takes twenty minutes, and it does not require anybody to feel monitored.
It is also a task the person who has lost their job can do, which sounds trivial and is not. Having something concrete and useful to do in the first week is worth more than the savings.
Set the review date now
A month out, in the calendar, agreed while nothing is tense. It stops the arrangement drifting into permanence, and it means neither person has to be the one who raises it later — which is the conversation nobody wants to start.
Easier with the numbers on the table
Money talk goes better when nobody is guessing.
Pairly puts what leaves, what is left and who has covered more in one place both of you can open. It never grades anybody's spending, and it never calls a purchase a mistake.