Okay, I had a TERRIBLE marriage, but one thing we got right was money. Eventually.
ALL money was joint money. (hear me out)
We had several linked bank accounts
1 acct was 'money in' (period. All incoming money went into that acct. it was never spent out of. Also helped protect us from fraud, as a side benefit)
1 acct was bills (mortgage, utilities, etc. NO 'personal' bills, like subscriptions and memberships)
1 acct was 'his'
1 acct was 'mine'
1 acct was kiddo's (ALL child related expenses; clothes, tuition, camps, daycare, medical... EVERYTHING.)
Then we also had 4 savings accounts. 2 personal. 1 joint (for vacations, dates, etc.), one for "OSF" (oh shoot! Fund... To cover the stuff that came up every durn month: car repairs, broken this, emergency that).
How 'it' worked was like this:
All money came into the joint account. Out of that we 'paid ourselves'... A SET amount, and completely equal. For us it was 100 every paycheck. For others they'll do 50-5000. Don't matter the total AS LONG AS ITS EQUAL. That goes into our personal accounts. No questions asked. Save, spend, whatever. Manage how you please. Buy whatever. ALL personal expenses (hair, clothing, work lunches, hobbies, magazines, memberships came out of our PERSONAL accounts).
Our bill money went into the bill account. A set amount went into our son's account.
Didn't leave a lot left over, and what was ALL went into OSF savings. (At the end of the month, OSF savings then went into joint savings, with a set amount left in.
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This took us a few years (of my husband spending THOUSANDS and running us into the ground, and me not ever having $20) to work this system out. He had a HARD time adjusting. He blew all of his money the first week in lunches.
But he adjusted. And it made everything fair. Joint expenses jointly. Personal expenses out of an 'even' fund... With no strings attached.
No credit cards.