CoverMapKey takeaway: A common starting target is 3–6 months of essential living costs, held somewhere accessible — not invested, and not locked in a fixed-rate account you can't break.
Why size matters
Too small, and an unexpected bill or income gap forces you into debt. Too large, and you're leaving money earning savings-account rates that could otherwise be working harder in an ISA or investment, once your buffer is adequate.
A simple starting framework
- 3 months' costs — a reasonable minimum if your income is stable (e.g. permanent employment, dual-income household).
- 6 months' costs — more appropriate if your income is variable (self-employed, contract, single income, or supporting dependants).
- Where to keep it — an easy-access savings account or easy-access cash ISA, not a fixed-rate account or investments, since you need to be able to reach it without penalty or market-timing risk.