I agree, a great question, and a topic often ignored.
people do things in very different ways, and this one is particularly sensitive.
This is what we do:
We both pay our full nett pay, into a joint account, all payments we receive goes in here, including Childrens Allowance.
Out of that account, we pay, all household bills, mortgage,health insurance, car & house insurance, motor tax, sim free phone bills, car servicing etc, all flights, hotels and meals out, drinks out - (where we both attend). We no longer have any seperate car fuel costs, as we recently both got Electric Cars, that just goes onto the electricity bill.
From that main joint account account, we are both paid a fixed amount each week, and we each split the weekly shopping bill from those funds, if we go out seperately, or buy something for ourselves, we pay for that ourselves.
So, we have our own funds, to spend, as we like, but all funds go into joint account.
We’ve been doing this for more than 10 years. Prior to that, we were transferring a fixed amount each into a joint account, that became problematic, when incomes varied, as we both have gone ahead or behind the other at various times over the years. The current setup, is all nett pay and any other payments go into main joint account, and almost everything is paid for out of that, except whatever we do individually.
The main joint account has built up, and as we have both lost our jobs on different occasions, we simply reduced the amount paid out to us individually, when that happened, cut our cloth, so to speak.
It brings a lot of certainty, and a sense of fairness & trust, and has become easier to manage some “income shocks”, which has happened a few times.
The system, is not for everyone, but works for us.