Available, twelve hundred and forty pounds

It's the twentieth of the month and you're in a shop with a coat. It's a good coat and it's two hundred and twenty pounds. You open the app. Available, twelve hundred and forty pounds, in green. You buy the coat. The number in green becomes a thousand and twenty. The number under it, in ordinary black, becomes three thousand nine hundred and eighty, and you don't look at that one, because that one is the balance, and the balance is the card's business.

On the twenty-eighth the minimum goes out, a hundred and something, by direct debit, and you don't look at that either, because it happens on its own. Some months you pay a bit more, when there's a bit more. The balance has been between three and four thousand for as long as you can remember. Two years ago there was a second card, in the post, pre-approved, with a limit of two thousand, and it's got twelve hundred on it, and its minimum goes out on the third.

If someone asked, you'd say you're fine. You've never missed a payment. The cards are within their limits. It's just how you run things, and it's how most people you know run things, and the coat was a good coat.

These are invented, but I'd guess yours is close. Some words. The limit is what the card company will let you owe. Available is the number in green, the limit minus what you owe. The balance is what you owe, in black, underneath. The minimum is the payment that goes out on its own. Zero is a card with nothing owed on it, which you may not have seen for a while. The gap is the space between the balance and the limit, the twelve hundred and forty pounds, which is the thing this book is about, because it feels like money and isn't. The statement is the monthly reckoning you get by email and don't open. Putting it away and the freeze are what chapter 19 does with the card. The fixed amount is what chapter 20 pays on payday. Dearest first is the order chapter 20 pays in. And the two lines, what's owed and what's available, written next to each other, is the exercise below.

Before you go on, do it. For every card you have, write on one sheet what you owe, what the limit is, what the interest rate is, and what the minimum is. Four columns, one row per card. Most people who do this have never seen the owed column added up, and the total is a number they'd have said was someone else's. Keep the sheet. It's the whole book on one page, and chapter 20 needs it.