Credit cards
A credit card is an account whose balance is your debt, held as a negative figure. Everything else follows from that.
Setting it up
Pick the bank from the catalogue, then enter:
- Credit limit, which produces the available figure on the card carousel.
- Current debt, entered as a positive number and stored as what it is.
- Annual effective rate, as your bank quotes it.
- Optionally, the statement day and the payment day.
The card can also carry a look: network, Visa, Mastercard, Amex, Diners, and a tier, which decides the gradient it is drawn with. Debit cards get a colour instead of a network, so a debit card is never mistaken for a credit card at a glance.
Spending, and why it is not double counted
A purchase with the card is an expense on the day you make it. That is the moment the money was committed, and it is the entry your reports should reflect.
Paying the card is a transfer, not a second expense: money moves from the account you pay with to the card, reducing the debt. Recording the payment as an expense would count the same money twice, which is the single most common way credit cards corrupt a budget.
The monthly reminder
With a payment day set, the app schedules a monthly reminder. With a rate as well, the reminder includes the estimated interest for the month, computed from your current debt.
It is an estimate, and it says so. Your statement includes charges and conventions the app cannot know.
Reconciling with the statement
When your statement disagrees with the app, open the card and use Adjust balance. On a credit card it reasons in debt, exactly like your statement: it shows the debt the app thinks you have, asks for the real one, and previews the difference as your debt goes up or your debt goes down.
Cards and your balances
The debt on a credit card reduces your available money in the balance figures, which is the honest reading: money you owe is not money you have.