You can do all of this and more with something like gnucash, and also foreign exchange fees, tax accounts,etc. I ran a small business off this for a while some

You can do all of this and more with something like gnucash, and also foreign exchange fees, tax accounts,etc. I ran a small business off this for a while some years ago without much trouble, mostly because I wanted to understand what was going on. You could also do invoicing and AR/AP which is t needed for home finances. Process was pretty easy. Some entries manual or automatic during the month. At whatever period you want download OFX/QFX from bank accounts, CC accounts, etc. and import. Or CSV files or whatever you can get from your banks. When you get statements, reconcile those accounts. Double entry is the only way to really keep track of things and catch errors, but you control granularity so in some sense amount of work. So in your scenarios, you would have expense accounts for interest fees per bank, loans, income accounts for different sources etc. the number of accounts you have is not a reflection of the institutions (eg banks) but the the things you want to keep track of. If you want things accurate, you pretty much have to add a reconciliation step somewhere, tools like gnucash will let you see what has been reconciled and what hasn’t yet.