Investing by Age
20s, 30s, 40s & Beyond

The correct answer is "as soon as you have an emergency fund and no high-interest debt". For most UK workers that means starting in your early-to-mid 20s. The single biggest driver of long-term investing outcomes is time in the market, £100/month started at 25 grows to roughly £171,000 at 65 (at 7%), while the same £100/month started at 35 only reaches ~£81,000. That is more than double the result for the same monthly contribution, purely because of an extra 10 years of compounding.

A commonly cited UK benchmark is roughly one year of annual salary saved or invested by age 30, rising to three times salary by 40 and six times by 50. On a £30,000 salary that is £30k by 30. These numbers are guidelines, what matters more is your trajectory. Someone at 30 with £10k saved but contributing £500/month is in a stronger position than someone with £40k saved but no longer adding to it. See our <a href="/how-much-to-save-by-30-uk">detailed age-30 guide</a> for the full breakdown.

No. You still have 25+ years until typical retirement age, which is more than enough time for compound interest to work. £400/month invested at 40, with a 7% return, grows to approximately £300,000 by age 65. Add a workplace pension with employer match and the numbers get considerably better. The 40s strategy is different from the 20s strategy, you typically cannot wait decades for a crash to recover, so you need a more balanced allocation and a clear income-replacement target.

Generally yes. The closer you are to needing the money, the less time you have to ride out a market crash, so it usually makes sense to shift some of your portfolio toward less volatile assets (bonds, cash) in the 5-10 years before retirement. This is called a "glide path". However, if your pension pot is expected to last 30+ years in retirement, you still need significant equity exposure in your 50s and 60s, going fully into cash at 55 is a classic mistake that exposes you to inflation risk over a long retirement.

Not starting. The second most common is stopping, pausing contributions during a market downturn, or cashing out when markets crash. The third is trying to time the market. In every decade, the answer is the same: pick a sensible contribution amount, invest it automatically every month into a diversified global index fund inside an ISA or pension, and leave it alone. The specifics of allocation, amounts and accounts change by decade, but the discipline does not.