How separate individual expenses from family expenses in Gnucash?

Question

After discussing the finances with my spouse I realized that there is no way to easily determine whether an item was purchased as part of our individual accounts, or our combined family account.

What is the best way to plan this in GNUCash? I'm worried about overcomplicating it. In the past when I had different currencies I added an Expense-CNY and from then on whenever I was typing Expense that would be the first one to pop up even though that was a travel exception.

I'm thinking maybe every category would have sub categories so that:

• Expenses:Auto:Gas:Family
• Expenses:Entertainment:Movies:Me
• Expenses:Entertainment:Movies:Family
• Expenses:Entertainment:Movies:Spouse

But that would mean a potential of three additional sub-accounts for each account/sub-account.

So it could become nightmarish like:

• Expenses:Auto:Gas:Family (x3)
• Expenses:Auto:Family (x3)
• Expenses:Entertainment:Movies:Family (x3)
• Expenses:Entertainment:Family (x3)

Answer 1

In your words, you want to "easily determine whether an item was purchased as part of our individual accounts, or our combined family account." It's not clear exactly to me what kind of reporting you're trying to get. (I find a useful approach here to be to start with the output you're trying to get from a system, and then see how that maps to the input you want to give the system.) Here's some possibilities:

1. You want to primarily report on who is making expenses. You want a summary of total expenses for You, Spouse, and Family. Then, I think it makes the most sense for the top level of your Expenses hierarchy to be the "who". This does mean that for each and every expense you need to find "who" it belongs to, and a 3 times the number of categories (assuming all categories could belong to any group), but really that's what you want for output, so it'd make sense that you'd need that for input. This makes it easy to see "total my expenses" vs. "total spouse expenses", but makes it harder to see "total gas expenses".
   • Expenses
     • Me
       • Gas
       • Movies
     • Spouse
       • Gas
       • Movies
     • Family
       • Gas
       • Movies
2. You want to primarily report on categories (you care more about "Total gas expenses" than "My expenses"), but want to see detail of "who" for each category on a case-by-case basis. Maybe you only want detail for some categories, but not others. This then would have the groupings going the other way, with the "who" at the leaf level rather than in the middle. This makes it easy to see "total gas expenses" vs. "total movie expenses", but makes it harder to see "total my expenses".
   • Expenses
     • Gas
       • Me
       • Spouse
       • Family
     • Movies
       • Me
       • Spouse
       • Family
3. You really only want to track your expenses, but your spouse's expenses show up in your reports. You say you don't want to overcomplicate things, so don't. If you are really only interested in your own expenses, then just track those, and have one generic Expense account for Family and/or Spouse, that everything for those "buckets" goes. Or, maybe you just want to track Family expenses, and aren't as worried about the details of the "discretionary spending" for you two individually. It's really only worth tracking data to the extent that you think you might ever want to report on it.
   • Expenses
     • Gas
     • Movies
     • Spouse discretionary
     • Me discretionary
4. You want to separate out assets by person so that each has their own "pool" of money, but track it in one accounting book. While I can't imagine it making any sense for my personal situation, I do hear that there are couple that happily work with "his", "hers", and "ours" pools of money, going so far as to have those as separate checking accounts. I'm not sure if that's what you're doing now, or if you're asking if that's a thing that people can track in Gnucash. Even if you're using one actual Checking account, you can use subaccounts to divide up the real account into pools for each of you. Just use "include subaccount" when reconciling the top-level Checking account to your bank statement. Then, you get reporting by filtering on which asset account the transfer to the expenses was from.
   • Assets
     • Checking
       • Me
       • Spouse
       • Family
   • Expenses
     • Gas
     • Movies
5. You want to separate out everything by person into their own accounting book. I'm pretty much just mentioning this for completeness, since it is certainly overcomplicating things. But, you could consider your family as a "business", that you and your spouse are contributing equity to, and track it as its own Gnucash book. You and your spouse would use your own Gnucash accounting books, and transfer money to the "Family", and then the Family book would see that as "Income" or "Equity" (there's probably a bunch of ways to do it, and you may want to play around some) to its own Asset accounts, from which it would spend on Expenses. A lot more work than I would think would be worth it, but I suppose some people might find the idea useful.

Answer 2

These sort of issues in structuring your personal finances relative to expenses can get complicated quickly, as your example demonstrates. I would recommend a solution that reduces duplication as much as possible- and depending on what information you're interested in tracking you could set it up in very different ways.

One solution would be to create virtual sub accounts of your assets, and to record the source of money rather than the destination. Thus, when you do an expense report, you can limit on the "his" or "hers" asset accounts, and see only the expenses which pertain to those accounts (likewise for liabilities/credit cards).

If, on the other hand, you're more interested in a running sum of expenses- rather than create "Me" and "Spouse" accounts at every leaf of the expense tree, it would make much more sense to create top level accounts for Expenses:His:etc and Expenses:Hers:etc. Using this model, you could create only the sub expense accounts that apply for each of your spending (with matching account structures for common accounts).