Keep a modest cash stash at home, in ones, fives, and tens — because a card reader is a small computer that phones another computer before it says yes. That call needs the store to have power, the network to be up, and the lines between them alive. A good storm can interrupt any of the three, and then the only money that works is the paper kind.
This isn't a prediction about banks. It's just how the machines are wired.
How much, and in what
Enough to cover a few days of the basics without a card: a tank of gas, a few days of groceries, one pharmacy run. Add those three for your household and you have your number. The part people get wrong isn't the amount, it's the denominations:
- Ones, fives, and tens. Mostly fives and tens.
- Avoid large bills. When registers are down, stores fall back to a cash box and "exact change only" arrives fast. A big bill is exactly as spendable as no bill at all if nobody can break it.
Where it lives
With your important documents — the same waterproof, grab-it-in-one-motion place your IDs and insurance papers live. If you've printed our Household Redundancy Ledger, the cash belongs in that same folder or bag. One place, known to the adults of the household, boring enough that nobody borrows from it for pizza.
Where this falls short
Cash has the weaknesses cash always had: it can be lost, misplaced in a move, or quietly spent — which is why the stash stays modest and boring, not a savings account. It earns nothing sitting there; that's the price of the insurance. Keep it small enough that losing it entirely would sting, not hurt.
While you're doing analog fallbacks: this pairs naturally with paper copies of your key documents and a written contact list. The communications-down situation page covers what else stops working when the towers go quiet, and what to do about it.