Card payment has become close to universal, and it is worth understanding what it actually depends on: mains electricity at the till, a data connection from the shop to its bank, functioning systems at both banks, and a card machine that has not been affected by any of the above.
A local power cut takes out all of them simultaneously, along with the cash machine on the corner. That is not a speculative scenario, it is an ordinary winter storm, and the shop that can still sell you bread that afternoon is the one with a till drawer and a pen.
What actually fails
Card outages also happen without a power cut. Payment networks, individual banks and card processors all have outages, and when a major one goes down at a busy time, a great many people discover simultaneously that they are carrying nothing else.
Local failures are the likely case. A storm, a cable fault, a substation problem: your street has no power, the shops on the parade have no power, and the town two miles away is entirely normal. Cash bridges that afternoon.
In a wider or longer event, cash becomes more useful still at first, and then less useful over time, which is the honest arc and is covered at the end of this page.
How much, honestly
Enough to be useful, not enough to be a target or a loss.
- A few days of ordinary spending for the household is the sensible baseline: food, fuel, a taxi, a locksmith, a tradesperson, a night somewhere.
- Think in terms of what you would actually need to buy rather than a round number. Food for the family for a few days, a tank of fuel, and something spare.
- More than most people carry, which is nothing, and far less than a stash.
- Keep some in each go-bag as well as at home, and a small amount in the car. See go-bags in this domain.
- Some in a wallet, permanently, so a card outage in a shop is an inconvenience rather than a problem.
Do not build a large cash hoard at home. It is uninsured beyond a low limit, it is a theft target, it earns nothing, and in the wider scenarios where people imagine it being useful, its value falls anyway. The point of household cash is to bridge days, not to be a store of wealth.
Small denominations
The detail that decides whether the cash works.
Nobody can change a fifty pound note in a power cut. The shop's card machine is dead, its float is what it started the morning with, and a large note is worse than useless.
- Mostly ten and twenty pound notes, and a genuine quantity of fives.
- A bag of coins. For meters, phones, parking, vending, and for making up an exact amount when nobody can give change.
- Split it up rather than keeping it as one bundle, so you can hand over a small amount without displaying the rest.
- Keep some very small money accessible, in a coat or a bag, separate from the main amount.
Test it mentally: could you buy twenty pounds of shopping, from a shop with no power, without needing change from anybody? If the answer needs a fifty, restructure it.
Where to keep it
- Not all in one place. Some at home, some in each go-bag, some in the car, some on each adult.
- Not in the obvious places. The bedside drawer, the jewellery box and the desk are where anybody looks.
- Somewhere you would find it in the dark, because a power cut is exactly when you want it.
- Tell at least one other adult in the household where it is. Cash nobody else knows about is cash that does not help when you are not there.
- In a fireproof document box or a bolted safe if the amount justifies it, noting that a document safe and a cash safe are rated for different things.
- Keep it dry, in a sealed bag, particularly anywhere it might get damp.
Write it on the household index sheet in general terms, so an executor or a partner knows to look, without the sheet itself being a treasure map. See what documents to hold.
Insurance
Check the limit. Home contents policies typically cover cash at the property only up to a low sum, often a few hundred pounds, and some require it to be in a locked safe for any cover at all.
- Read the policy wording rather than assuming.
- Money in a safe may be covered for more, and the safe may need to meet a specification and be fixed down.
- Cash taken from the house is usually covered differently or not at all.
This is a genuine argument for a modest amount. Beyond the policy limit you are self-insuring, and against the two likeliest losses, which are theft and fire.
Keeping it valid
Small housekeeping that avoids an annoying surprise.
- Notes get withdrawn. Paper notes have been replaced by polymer, and once a note is withdrawn from circulation most shops and many banks will not take it. The Bank of England will exchange withdrawn notes indefinitely, and that is a trip and a form rather than something you can do on the day.
- Check your stash occasionally and swap out anything old.
- Scottish and Northern Irish notes are legal currency and are accepted across the UK in practice, and some retailers elsewhere refuse them out of unfamiliarity. Worth knowing if you are relying on them away from home.
- Rotate it. Spend it and replace it once a year so it does not sit for a decade.
The rest of the picture
Cash is one layer, and the others matter.
- More than one bank. Accounts with two unconnected institutions means a single bank outage does not leave you with nothing. This is genuinely worth doing and costs nothing.
- A card from each, carried separately.
- A credit card kept for emergencies, cleared and unused, which is a different kind of buffer.
- Know your account numbers, or have them written down, because you can sometimes be identified without a card.
- Standing orders and direct debits keep running when you cannot. Know what leaves the account and when.
- Somebody who could help. In practice the most reliable emergency fund most people have is a relative or friend, which is another instance of the pattern in community and mutual aid.
What cash does not solve
Being honest about the limits, because cash is often presented as the answer to more than it is.
It bridges days and short local failures. That is what it is genuinely good for and it is a real benefit for a modest effort.
In a longer or wider event its usefulness declines. If the shops have nothing to sell, cash buys nothing. If a wider financial disruption is under way, its value is uncertain. Physical currency is a claim on a functioning system, not a substitute for one.
Which is why cash sits behind stores rather than in front of them. A household with a few weeks of food, water and fuel and a modest amount of cash is in a far better position than one with a large amount of cash and empty cupboards. See the food chapter.
And in a genuinely extended situation, what has value is what you can do and what you have. Skills, tools, medicines, fuel, seed and the ability to repair things. Every other domain in this app is about that, and this page is deliberately the smallest one.