Core Concepts
Financy is built on real double-entry accounting — the same model used by professional ledgers. Understanding a few ideas makes everything else click.
Double-entry
Every transaction is made of postings — signed amounts against accounts — that must sum to zero. Money always comes from somewhere and goes to somewhere.
For example, paying $84.20 for groceries from checking is two postings:
| Account | Amount |
|---|---|
| Groceries (expense) | +84.20 |
| Checking (asset) | −84.20 |
They cancel out to zero, so the books always balance. Financy writes these postings for you — you just pick Income / Expense / Transfer in the entry form.
Balances are derived, never stored
Financy never stores a “balance” field that could get out of sync. Every balance, total, and net-worth figure is recomputed by summing postings. Delete or edit a transaction and everything downstream updates automatically and correctly.
Account types
| Type | Examples | Normal direction |
|---|---|---|
| Asset | Checking, Savings, Cash | + increases |
| Liability | Credit card, Loan | + increases what you owe |
| Income | Salary, Interest | source of money |
| Expense | Groceries, Rent | use of money |
| Equity | Opening Balances | starting values |
Assets and liabilities are your money accounts (real balances). Income and expense accounts are your categories. Net worth = total assets − total liabilities.
Money is stored as integer cents
Amounts are kept as integer minor units (cents for USD, whole rupiah for Rp), never floating-point. This avoids rounding errors entirely. How they’re displayed (symbol, decimals, separators) is controlled by Settings.
Opening balances
When you create an account with a starting balance, Financy posts a real Opening Balance transaction against the Equity account — it doesn’t just “set” a number. That keeps the double-entry invariant intact from day one.