How big should your emergency fund be?
The least exciting pot of money you will ever build, and the one that makes everything else possible.
Before investing, before overpaying the mortgage, before almost anything else in personal finance, there is a boring pot of cash that makes everything after it possible. Here is how to size yours.
The short version
- Employed, stable job, dual income: around 3 months of essential spending.
- Single income, or a household depending on one salary: 6 months.
- Self-employed or irregular income: 6–12 months.
- Keep it in easy-access cash — not investments, not locked away.
Count essential spending, not your salary
The most common mistake is sizing the fund against income. What you actually need to cover is the floor of your outgoings: rent or mortgage, council tax, utilities, food, insurance, transport, minimum debt payments. Streaming subscriptions, holidays and meals out are not part of the number, because in the situation where you need this money, they stop.
For many households the essential figure is 50–65% of normal monthly spending. Working it out honestly usually makes the target less intimidating than it first sounds.
Where to keep it
Three requirements, in this order: you can reach it within a day or two, its value cannot fall, and it earns something. That points to an easy-access savings account or an easy-access cash ISA. With cash rates having reached roughly 4–4.75% in 2026, the gap between a good account and a poor one is real money — the average high-street instant-access account still pays a fraction of the best available.
What it should not be: a stocks and shares ISA (the market may be down exactly when you need it), a fixed-term bond you cannot break, or a current account paying nothing.
Work out how long it takes to build
Put your target and a realistic monthly amount into the savings goal calculator to see the date you'd hit it.
Open the savings goal calculator →Emergency fund or debt first?
If you are carrying credit card or overdraft debt at 20%+ interest, paying that down beats earning 4.5% on savings by a wide margin. The usual compromise is to build a smaller starter buffer — often around £1,000 — clear the expensive debt, then build the full fund. The buffer exists so that the next unexpected bill does not put you straight back on the card.
What counts as an emergency
A boiler failing, a car needed for work breaking down, losing your job, an urgent trip for a family illness. Not: a holiday, a sale, a new phone, Christmas. Those are predictable and belong in separate sinking funds — small monthly amounts set aside for known future costs. Keeping them separate is what stops the emergency fund quietly draining away.
When it's full, stop
An emergency fund is insurance, not an investment. Once you have the months you need, more cash sitting there is money losing purchasing power to inflation year after year. That is the point at which surplus should go towards pension contributions, an ISA, or the mortgage.
Common questions
How much should I have in an emergency fund in the UK?
Three months of essential spending is a reasonable baseline for a stable dual-income household, six months for a single income, and six to twelve months if you are self-employed. Size it against essential outgoings rather than your salary.
Where should I keep my emergency fund?
In easy-access cash — a savings account or easy-access cash ISA. It needs to be reachable quickly and cannot be exposed to market falls, which rules out investing it.
Should I build an emergency fund or pay off debt first?
If the debt carries high interest, such as a credit card or overdraft, clearing it usually beats saving. A common approach is a small starter buffer of around £1,000 first, then the debt, then the full fund.
Is an emergency fund still worth it with inflation?
Yes, for the amount you actually need. Its job is access and certainty, not growth. Beyond that amount, holding extra cash long-term does lose purchasing power, which is why the fund should have a ceiling.